diff --git a/libnd4j/blas/Environment.cpp b/libnd4j/blas/Environment.cpp
index f423c73dd..3b9502534 100644
--- a/libnd4j/blas/Environment.cpp
+++ b/libnd4j/blas/Environment.cpp
@@ -26,6 +26,7 @@
 #include <helpers/StringUtils.h>
 #include <thread>
 #include <helpers/logger.h>
+#include <memory/MemoryCounter.h>
 
 #ifdef _OPENMP
 
@@ -291,11 +292,19 @@ namespace nd4j {
     }
 
     void Environment::setMaxThreads(int max) {
+        // FIXME: not possible at this moment, since maxThreads is limited by number of threads in pool. however we can allocate more threads if we want
         //_maxThreads.store(max);
     }
 
     void Environment::setMaxMasterThreads(int max) {
-        //_maxMasterThreads = max;
+        if (max > maxThreads()) {
+            max = maxThreads();
+        }
+
+        if (max < 1)
+            return;
+
+        _maxMasterThreads = max;
     }
 
     bool Environment::precisionBoostAllowed() {
@@ -334,6 +343,38 @@ namespace nd4j {
         _allowHelpers.store(reallyAllow);
     }
 
+    void Environment::setGroupLimit(int group, Nd4jLong numBytes) {
+        nd4j::memory::MemoryCounter::getInstance()->setGroupLimit((nd4j::memory::MemoryType) group, numBytes);
+    }
+
+    void Environment::setDeviceLimit(int deviceId, Nd4jLong numBytes) {
+        nd4j::memory::MemoryCounter::getInstance()->setDeviceLimit(deviceId, numBytes);
+    }
+
+    Nd4jLong Environment::getGroupLimit(int group) {
+        return nd4j::memory::MemoryCounter::getInstance()->groupLimit((nd4j::memory::MemoryType) group);
+    }
+
+    Nd4jLong Environment::getDeviceLimit(int deviceId) {
+        return nd4j::memory::MemoryCounter::getInstance()->deviceLimit(deviceId);
+    }
+
+    Nd4jLong Environment::getGroupCounter(int group) {
+        return nd4j::memory::MemoryCounter::getInstance()->allocatedGroup((nd4j::memory::MemoryType) group);
+    }
+
+    Nd4jLong Environment::getDeviceCounter(int deviceId) {
+        return nd4j::memory::MemoryCounter::getInstance()->allocatedDevice(deviceId);
+    }
+
+    uint64_t Environment::maxPrimaryMemory() {
+        return _maxTotalPrimaryMemory.load();
+    }
+
+    uint64_t Environment::maxSpecialMemory() {
+        return _maxTotalSpecialMemory.load();
+    }
+
     nd4j::Environment *nd4j::Environment::_instance = 0;
 
 }
diff --git a/libnd4j/blas/Environment.h b/libnd4j/blas/Environment.h
index 54982471f..5bef3f1e4 100644
--- a/libnd4j/blas/Environment.h
+++ b/libnd4j/blas/Environment.h
@@ -27,6 +27,7 @@
 #include <stdexcept>
 #include <array/DataType.h>
 #include <types/pair.h>
+#include <pointercast.h>
 
 namespace nd4j{
     class ND4J_EXPORT Environment {
@@ -97,10 +98,30 @@ namespace nd4j{
         int maxMasterThreads();
         void setMaxMasterThreads(int max);
 
+        /*
+         * Legacy memory limits API, still used in new API as simplified version
+         */
         void setMaxPrimaryMemory(uint64_t maxBytes);
         void setMaxSpecialyMemory(uint64_t maxBytes);
         void setMaxDeviceMemory(uint64_t maxBytes);
 
+        uint64_t maxPrimaryMemory();
+        uint64_t maxSpecialMemory();
+        ////////////////////////
+
+        /*
+         * Methods for memory limits/counters
+         */
+        void setGroupLimit(int group, Nd4jLong numBytes);
+        void setDeviceLimit(int deviceId, Nd4jLong numBytes);
+
+        Nd4jLong getGroupLimit(int group);
+        Nd4jLong getDeviceLimit(int deviceId);
+
+        Nd4jLong getGroupCounter(int group);
+        Nd4jLong  getDeviceCounter(int deviceId);
+        ////////////////////////
+
         bool isUseMKLDNN() { return _useMKLDNN.load(); }
         void setUseMKLDNN(bool useMKLDNN) { _useMKLDNN.store(useMKLDNN); }
 
diff --git a/libnd4j/blas/NDArray.h b/libnd4j/blas/NDArray.h
index 037e6e1d0..671f72a57 100644
--- a/libnd4j/blas/NDArray.h
+++ b/libnd4j/blas/NDArray.h
@@ -44,6 +44,7 @@
 #include <execution/AffinityManager.h>
 #include <memory>
 #include <array/InteropDataBuffer.h>
+#include <memory/MemoryCounter.h>
 
 
 namespace nd4j {
diff --git a/libnd4j/blas/NativeOps.h b/libnd4j/blas/NativeOps.h
index 10893c08d..cd6274dfb 100755
--- a/libnd4j/blas/NativeOps.h
+++ b/libnd4j/blas/NativeOps.h
@@ -76,6 +76,7 @@ bool verbose = false;
 #include <graph/execution/LogicExecutor.h>
 #include <graph/ResultWrapper.h>
 #include <DebugInfo.h>
+#include <memory/MemoryCounter.h>
 
 typedef nd4j::InteropDataBuffer OpaqueDataBuffer;
 
diff --git a/libnd4j/blas/cpu/NativeOps.cpp b/libnd4j/blas/cpu/NativeOps.cpp
index e150a2039..1b1d22fbf 100644
--- a/libnd4j/blas/cpu/NativeOps.cpp
+++ b/libnd4j/blas/cpu/NativeOps.cpp
@@ -3093,8 +3093,14 @@ bool isOptimalRequirementsMet() {
 }
 
 OpaqueDataBuffer* allocateDataBuffer(Nd4jLong elements, int dataType, bool allocateBoth) {
-    auto dtype = DataTypeUtils::fromInt(dataType);
-    return new nd4j::InteropDataBuffer(elements * DataTypeUtils::sizeOf(dtype) , dtype, allocateBoth);
+    try {
+        auto dtype = DataTypeUtils::fromInt(dataType);
+        return new nd4j::InteropDataBuffer(elements * DataTypeUtils::sizeOf(dtype) , dtype, allocateBoth);
+    } catch (std::exception &e) {
+        nd4j::LaunchContext::defaultContext()->errorReference()->setErrorCode(1);
+        nd4j::LaunchContext::defaultContext()->errorReference()->setErrorMessage(e.what());
+        return nullptr;
+    }
 }
 
 Nd4jPointer dbPrimaryBuffer(OpaqueDataBuffer *dataBuffer) {
@@ -3126,7 +3132,12 @@ void dbAllocateSpecialBuffer(OpaqueDataBuffer *dataBuffer) {
 }
 
 void dbExpandBuffer(OpaqueDataBuffer *dataBuffer, Nd4jLong elements) {
-    dataBuffer->dataBuffer()->expand(elements * DataTypeUtils::sizeOf(dataBuffer->dataBuffer()->getDataType()));
+    try {
+        dataBuffer->dataBuffer()->expand(elements * DataTypeUtils::sizeOf(dataBuffer->dataBuffer()->getDataType()));
+    } catch (std::exception &e) {
+        nd4j::LaunchContext::defaultContext()->errorReference()->setErrorCode(1);
+        nd4j::LaunchContext::defaultContext()->errorReference()->setErrorMessage(e.what());
+    }
 }
 
 OpaqueDataBuffer* dbCreateView(OpaqueDataBuffer *dataBuffer, Nd4jLong length, Nd4jLong offset) {
diff --git a/libnd4j/blas/cuda/NativeOps.cu b/libnd4j/blas/cuda/NativeOps.cu
index 1f8149865..419cadef5 100755
--- a/libnd4j/blas/cuda/NativeOps.cu
+++ b/libnd4j/blas/cuda/NativeOps.cu
@@ -3781,8 +3781,14 @@ void ctxAllowHelpers(OpaqueContext* ptr, bool reallyAllow) {
 }
 
 OpaqueDataBuffer* allocateDataBuffer(Nd4jLong elements, int dataType, bool allocateBoth) {
-    auto dtype = DataTypeUtils::fromInt(dataType);
-    return new nd4j::InteropDataBuffer(elements * DataTypeUtils::sizeOf(dtype) , dtype, allocateBoth);
+    try {
+        auto dtype = DataTypeUtils::fromInt(dataType);
+        return new nd4j::InteropDataBuffer(elements * DataTypeUtils::sizeOf(dtype), dtype, allocateBoth);
+    } catch (std::exception &e) {
+        nd4j::LaunchContext::defaultContext()->errorReference()->setErrorCode(1);
+        nd4j::LaunchContext::defaultContext()->errorReference()->setErrorMessage(e.what());
+        return nullptr;
+    }
 }
 
 Nd4jPointer dbPrimaryBuffer(OpaqueDataBuffer *dataBuffer) {
@@ -3814,7 +3820,12 @@ void dbAllocateSpecialBuffer(OpaqueDataBuffer *dataBuffer) {
 }
 
 void dbExpandBuffer(OpaqueDataBuffer *dataBuffer, Nd4jLong elements) {
-    dataBuffer->dataBuffer()->expand(elements * DataTypeUtils::sizeOf(dataBuffer->dataBuffer()->getDataType()));
+    try {
+        dataBuffer->dataBuffer()->expand(elements * DataTypeUtils::sizeOf(dataBuffer->dataBuffer()->getDataType()));
+    } catch (std::exception &e) {
+        nd4j::LaunchContext::defaultContext()->errorReference()->setErrorCode(1);
+        nd4j::LaunchContext::defaultContext()->errorReference()->setErrorMessage(e.what());
+    }
 }
 
 OpaqueDataBuffer* dbCreateView(OpaqueDataBuffer *dataBuffer, Nd4jLong length, Nd4jLong offset) {
diff --git a/libnd4j/include/array/ConstantDescriptor.h b/libnd4j/include/array/ConstantDescriptor.h
index f2f2f46a6..f32c1c8bf 100644
--- a/libnd4j/include/array/ConstantDescriptor.h
+++ b/libnd4j/include/array/ConstantDescriptor.h
@@ -22,7 +22,7 @@
 #define DEV_TESTS_CONSTANTDESCRIPTOR_H
 
 #include <array/DataType.h>
-#include <map>
+#include <unordered_map>
 #include <vector>
 #include <pointercast.h>
 #include <dll.h>
diff --git a/libnd4j/include/array/NDArrayList.h b/libnd4j/include/array/NDArrayList.h
index 358469602..843b69a91 100644
--- a/libnd4j/include/array/NDArrayList.h
+++ b/libnd4j/include/array/NDArrayList.h
@@ -25,7 +25,7 @@
 
 #include <string>
 #include <atomic>
-#include <map>
+#include <unordered_map>
 #include <NDArray.h>
 #include <memory/Workspace.h>
 #include <dll.h>
diff --git a/libnd4j/include/array/ShapeDescriptor.h b/libnd4j/include/array/ShapeDescriptor.h
index 25839cfa9..ddfd45a38 100644
--- a/libnd4j/include/array/ShapeDescriptor.h
+++ b/libnd4j/include/array/ShapeDescriptor.h
@@ -21,7 +21,7 @@
 #ifndef DEV_TESTS_SHAPEDESCRIPTOR_H
 #define DEV_TESTS_SHAPEDESCRIPTOR_H
 
-#include <map>
+#include <unordered_map>
 #include <vector>
 #include <dll.h>
 #include <pointercast.h>
diff --git a/libnd4j/include/array/cuda/DataBuffer.cu b/libnd4j/include/array/cuda/DataBuffer.cu
index 2a3efa3c8..7cb66ac9d 100644
--- a/libnd4j/include/array/cuda/DataBuffer.cu
+++ b/libnd4j/include/array/cuda/DataBuffer.cu
@@ -23,6 +23,9 @@
 #include <DataTypeUtils.h>
 #include <op_boilerplate.h>
 #include <exceptions/cuda_exception.h>
+#include <execution/AffinityManager.h>
+#include <memory/MemoryCounter.h>
+#include <exceptions/allocation_exception.h>
 
 namespace nd4j {
     void DataBuffer::expand(const uint64_t size) {
@@ -64,8 +67,20 @@ namespace nd4j {
 void DataBuffer::allocateSpecial() {
 
     if (_specialBuffer == nullptr && getLenInBytes() > 0) {
+        auto deviceId = nd4j::AffinityManager::currentDeviceId();
+
+        if (_workspace == nullptr)
+            if (!nd4j::memory::MemoryCounter::getInstance()->validate(getLenInBytes()))
+                throw nd4j::allocation_exception::build("Requested amount exceeds device limits", nd4j::memory::MemoryCounter::getInstance()->deviceLimit(deviceId), getLenInBytes());
+
+
         ALLOCATE_SPECIAL(_specialBuffer, _workspace, getLenInBytes(), int8_t);
         _isOwnerSpecial = true;
+
+        if (_workspace == nullptr) {
+            nd4j::memory::MemoryCounter::getInstance()->countIn(deviceId, getLenInBytes());
+            nd4j::memory::MemoryCounter::getInstance()->countIn(nd4j::memory::MemoryType::DEVICE, getLenInBytes());
+        }
     }
 }
 
diff --git a/libnd4j/include/array/impl/DataBuffer.cpp b/libnd4j/include/array/impl/DataBuffer.cpp
index fae25478f..49527026c 100644
--- a/libnd4j/include/array/impl/DataBuffer.cpp
+++ b/libnd4j/include/array/impl/DataBuffer.cpp
@@ -23,6 +23,8 @@
 #include <helpers/logger.h>
 #include <array/DataTypeUtils.h>
 #include <execution/AffinityManager.h>
+#include <memory/MemoryCounter.h>
+#include <exceptions/allocation_exception.h>
 
 namespace nd4j {
     ///// IMLEMENTATION OF COMMON METHODS /////
@@ -232,14 +234,35 @@ namespace nd4j {
     void DataBuffer::allocatePrimary() {
 
         if (_primaryBuffer == nullptr && getLenInBytes() > 0) {
+            auto deviceId = nd4j::AffinityManager::currentDeviceId();
+            // check if this allocation won't bring us above limit
+            if (_workspace == nullptr) {
+                if (Environment::getInstance()->isCPU()) {
+                    // on cpu backend we validate against device 0 for now
+                    if (!nd4j::memory::MemoryCounter::getInstance()->validate(getLenInBytes()))
+                        throw nd4j::allocation_exception::build("Requested amount exceeds HOST device limits", nd4j::memory::MemoryCounter::getInstance()->deviceLimit(deviceId), getLenInBytes());
+                } else {
+                    // in heterogenous mode we valdate against device group
+                    if (!nd4j::memory::MemoryCounter::getInstance()->validateGroup(nd4j::memory::MemoryType::HOST, getLenInBytes()))
+                        throw nd4j::allocation_exception::build("Requested amount exceeds HOST group limits", nd4j::memory::MemoryCounter::getInstance()->groupLimit(nd4j::memory::MemoryType::HOST), getLenInBytes());
+                }
+            }
+
             ALLOCATE(_primaryBuffer, _workspace, getLenInBytes(), int8_t);
             _isOwnerPrimary = true;
+
+            // count in towards current deviceId if we're not in workspace mode
+            if (_workspace == nullptr) {
+                if (Environment::getInstance()->isCPU()) // we don't want this counter to be added to CUDA device
+                    nd4j::memory::MemoryCounter::getInstance()->countIn(deviceId, getLenInBytes());
+
+                nd4j::memory::MemoryCounter::getInstance()->countIn(nd4j::memory::MemoryType::HOST, getLenInBytes());
+            }
         }
     }
 
 ////////////////////////////////////////////////////////////////////////
     void DataBuffer::setAllocFlags(const bool isOwnerPrimary, const bool isOwnerSpecial) {
-
         _isOwnerPrimary = isOwnerPrimary;
         _isOwnerSpecial = isOwnerSpecial;
     }
@@ -252,6 +275,15 @@ namespace nd4j {
             RELEASE(p, _workspace);
             _primaryBuffer = nullptr;
             _isOwnerPrimary = false;
+
+
+            // count out towards DataBuffer device, only if we're not in workspace
+            if (_workspace == nullptr) {
+                if (Environment::getInstance()->isCPU())
+                    nd4j::memory::MemoryCounter::getInstance()->countOut(_deviceId, getLenInBytes());
+
+                nd4j::memory::MemoryCounter::getInstance()->countOut(nd4j::memory::MemoryType::HOST, getLenInBytes());
+            }
         }
     }
 
diff --git a/libnd4j/include/exceptions/allocation_exception.h b/libnd4j/include/exceptions/allocation_exception.h
index 29756d253..458650037 100644
--- a/libnd4j/include/exceptions/allocation_exception.h
+++ b/libnd4j/include/exceptions/allocation_exception.h
@@ -40,6 +40,7 @@ namespace nd4j {
         ~allocation_exception() = default;
 
         static allocation_exception build(std::string message, Nd4jLong bytes);
+        static allocation_exception build(std::string message, Nd4jLong limit, Nd4jLong bytes);
     };
 }
 
diff --git a/libnd4j/include/exceptions/impl/allocation_exception.cpp b/libnd4j/include/exceptions/impl/allocation_exception.cpp
index 76c6338da..85c3e72aa 100644
--- a/libnd4j/include/exceptions/impl/allocation_exception.cpp
+++ b/libnd4j/include/exceptions/impl/allocation_exception.cpp
@@ -31,4 +31,11 @@ namespace nd4j {
         message += "; Requested bytes: [" + bytes + "]";
         return allocation_exception(message);
     }
+
+    allocation_exception allocation_exception::build(std::string message, Nd4jLong limit, Nd4jLong numBytes) {
+        auto bytes = StringUtils::valueToString<Nd4jLong>(numBytes);
+        auto lim = StringUtils::valueToString<Nd4jLong>(limit);
+        message += "; Limit bytes: [" + lim + "]; Requested bytes: [" + bytes + "]";
+        return allocation_exception(message);
+    }
 }
\ No newline at end of file
diff --git a/libnd4j/include/graph/ExecutionResult.h b/libnd4j/include/graph/ExecutionResult.h
index 7a632a998..b1a1b1737 100644
--- a/libnd4j/include/graph/ExecutionResult.h
+++ b/libnd4j/include/graph/ExecutionResult.h
@@ -23,7 +23,7 @@
 
 #include <vector>
 #include <initializer_list>
-#include <map>
+#include <unordered_map>
 #include <string>
 #include <flatbuffers/flatbuffers.h>
 #include <graph/Variable.h>
diff --git a/libnd4j/include/graph/Graph.h b/libnd4j/include/graph/Graph.h
index 18c23ec0f..00efb3c52 100644
--- a/libnd4j/include/graph/Graph.h
+++ b/libnd4j/include/graph/Graph.h
@@ -23,7 +23,7 @@
 
 #include <list>
 #include <algorithm>
-#include <map>
+#include <unordered_map>
 //#include <NDArray.h>
 #include <graph/Node.h>
 #include <graph/Stash.h>
diff --git a/libnd4j/include/graph/GraphHolder.h b/libnd4j/include/graph/GraphHolder.h
index a60d088e7..f740ad4ca 100644
--- a/libnd4j/include/graph/GraphHolder.h
+++ b/libnd4j/include/graph/GraphHolder.h
@@ -20,7 +20,7 @@
 
 #include <helpers/logger.h>
 #include <pointercast.h>
-#include <map>
+#include <unordered_map>
 #include <graph/Graph.h>
 #include <helpers/SimpleReadWriteLock.h>
 #include <exceptions/unknown_graph_exception.h>
diff --git a/libnd4j/include/graph/GraphState.h b/libnd4j/include/graph/GraphState.h
index 95f8a016d..52c6f9e16 100644
--- a/libnd4j/include/graph/GraphState.h
+++ b/libnd4j/include/graph/GraphState.h
@@ -25,7 +25,7 @@
 #include <op_boilerplate.h>
 #include <dll.h>
 #include <vector>
-#include <map>
+#include <unordered_map>
 #include <graph/Scope.h>
 #include <Status.h>
 #include <graph/VariableSpace.h>
diff --git a/libnd4j/include/graph/Scope.h b/libnd4j/include/graph/Scope.h
index 4e322b5b2..5cbbf8bc0 100644
--- a/libnd4j/include/graph/Scope.h
+++ b/libnd4j/include/graph/Scope.h
@@ -22,7 +22,7 @@
 #define LIBND4J_SCOPE_H
 
 #include <string>
-#include <map>
+#include <unordered_map>
 #include <graph/Node.h>
 
 namespace nd4j {
diff --git a/libnd4j/include/graph/Stash.h b/libnd4j/include/graph/Stash.h
index 6613ec859..83a7ec066 100644
--- a/libnd4j/include/graph/Stash.h
+++ b/libnd4j/include/graph/Stash.h
@@ -23,7 +23,7 @@
 
 //#include <graph/Block.h>
 #include <NDArray.h>
-#include <map>
+#include <unordered_map>
 #include <string>
 #include <atomic>
 #include <pointercast.h>
diff --git a/libnd4j/include/graph/VariableSpace.h b/libnd4j/include/graph/VariableSpace.h
index 21bdc608b..9443d34b1 100644
--- a/libnd4j/include/graph/VariableSpace.h
+++ b/libnd4j/include/graph/VariableSpace.h
@@ -26,7 +26,7 @@
 #include <string>
 #include <vector>
 #include <list>
-#include <map>
+#include <unordered_map>
 #include <mutex>
 #include <NDArray.h>
 #include <array/NDArrayList.h>
diff --git a/libnd4j/include/memory/MemoryCounter.h b/libnd4j/include/memory/MemoryCounter.h
new file mode 100644
index 000000000..bf8ff60dc
--- /dev/null
+++ b/libnd4j/include/memory/MemoryCounter.h
@@ -0,0 +1,146 @@
+/*******************************************************************************
+ * Copyright (c) 2020 Konduit K.K.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Apache License, Version 2.0 which is available at
+ * https://www.apache.org/licenses/LICENSE-2.0.
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ ******************************************************************************/
+
+//
+// @author raver119@gmail.com
+//
+
+#ifndef SD_MEMORYCOUNTER_H
+#define SD_MEMORYCOUNTER_H
+
+#include <pointercast.h>
+#include <dll.h>
+#include <map>
+#include <memory/MemoryType.h>
+#include <mutex>
+
+namespace nd4j {
+    namespace memory {
+        /**
+         * This class provides simple per-device counter
+         */
+        class ND4J_EXPORT MemoryCounter {
+        private:
+            static MemoryCounter* _INSTANCE;
+
+            // used for synchronization
+            std::mutex _locker;
+
+            // per-device counters
+            std::map<int, Nd4jLong> _deviceCounters;
+
+            // TODO: change this wrt heterogenous stuff on next iteration
+            // per-group counters
+            std::map<nd4j::memory::MemoryType, Nd4jLong> _groupCounters;
+
+            // per-device limits
+            std::map<int, Nd4jLong> _deviceLimits;
+
+            // per-group limits
+            std::map<nd4j::memory::MemoryType, Nd4jLong> _groupLimits;
+
+            MemoryCounter();
+            ~MemoryCounter() = default;
+
+        public:
+            static MemoryCounter *getInstance();
+
+            /**
+             * This method checks if allocation of numBytes won't break through per-group or per-device limit
+             * @param numBytes
+             * @return TRUE if allocated ammount will keep us below limit, FALSE otherwise
+             */
+            bool validate(Nd4jLong numBytes);
+
+            /**
+             * This method checks if allocation of numBytes won't break through  per-device limit
+             * @param deviceId
+             * @param numBytes
+             * @return TRUE if allocated ammount will keep us below limit, FALSE otherwise
+             */
+            bool validateDevice(int deviceId, Nd4jLong numBytes);
+
+            /**
+             * This method checks if allocation of numBytes won't break through per-group limit
+             * @param deviceId
+             * @param numBytes
+             * @return TRUE if allocated ammount will keep us below limit, FALSE otherwise
+             */
+            bool validateGroup(nd4j::memory::MemoryType group, Nd4jLong numBytes);
+
+            /**
+             * This method adds specified number of bytes to specified counter
+             * @param deviceId
+             * @param numBytes
+             */
+            void countIn(int deviceId, Nd4jLong numBytes);
+            void countIn(nd4j::memory::MemoryType group, Nd4jLong numBytes);
+
+            /**
+             * This method subtracts specified number of bytes from specified counter
+             * @param deviceId
+             * @param numBytes
+             */
+            void countOut(int deviceId, Nd4jLong numBytes);
+            void countOut(nd4j::memory::MemoryType group, Nd4jLong numBytes);
+
+            /**
+             * This method returns amount of memory allocated on specified device
+             * @param deviceId
+             * @return
+             */
+            Nd4jLong allocatedDevice(int deviceId);
+
+            /**
+             * This method returns amount of memory allocated in specified group of devices
+             * @param group
+             * @return
+             */
+            Nd4jLong allocatedGroup(nd4j::memory::MemoryType group);
+
+            /**
+             * This method allows to set per-device memory limits
+             * @param deviceId
+             * @param numBytes
+             */
+            void setDeviceLimit(int deviceId, Nd4jLong numBytes);
+
+            /**
+             * This method returns current device limit in bytes
+             * @param deviceId
+             * @return
+             */
+            Nd4jLong deviceLimit(int deviceId);
+
+            /**
+             * This method allows to set per-group memory limits
+             * @param group
+             * @param numBytes
+             */
+            void setGroupLimit(nd4j::memory::MemoryType group, Nd4jLong numBytes);
+
+            /**
+             * This method returns current group limit in bytes
+             * @param group
+             * @return
+             */
+            Nd4jLong groupLimit(nd4j::memory::MemoryType group);
+        };
+    }
+}
+
+
+#endif //SD_MEMORYCOUNTER_H
diff --git a/libnd4j/include/memory/MemoryTracker.h b/libnd4j/include/memory/MemoryTracker.h
index 78ade5bcc..097d2903d 100644
--- a/libnd4j/include/memory/MemoryTracker.h
+++ b/libnd4j/include/memory/MemoryTracker.h
@@ -30,6 +30,9 @@
 
 namespace nd4j {
     namespace memory {
+        /**
+         * This class is used for tracking memory allocation wrt their allocation points in code
+         */
         class ND4J_EXPORT MemoryTracker {
         private:
             static MemoryTracker* _INSTANCE;
diff --git a/libnd4j/include/memory/impl/MemoryCounter.cpp b/libnd4j/include/memory/impl/MemoryCounter.cpp
new file mode 100644
index 000000000..0dc845e37
--- /dev/null
+++ b/libnd4j/include/memory/impl/MemoryCounter.cpp
@@ -0,0 +1,133 @@
+/*******************************************************************************
+ * Copyright (c) 2020 Konduit K.K.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Apache License, Version 2.0 which is available at
+ * https://www.apache.org/licenses/LICENSE-2.0.
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ ******************************************************************************/
+
+//
+// @author raver119@gmail.com
+//
+
+#include "../MemoryCounter.h"
+#include <execution/AffinityManager.h>
+#include <Environment.h>
+#include <helpers/logger.h>
+
+namespace nd4j {
+    namespace memory {
+
+        MemoryCounter::MemoryCounter() {
+            auto numDevices = nd4j::AffinityManager::numberOfDevices();
+
+            // setting default 0s
+            for (int e = 0; e < numDevices; e++) {
+                _deviceLimits[e] = 0;
+                _deviceCounters[e] = 0;
+            }
+
+            // setting initial values for limits
+            _groupLimits[nd4j::memory::MemoryType::HOST] = nd4j::Environment::getInstance()->maxPrimaryMemory();
+            _groupLimits[nd4j::memory::MemoryType::DEVICE] = nd4j::Environment::getInstance()->maxSpecialMemory();
+
+            // setting initial counter values
+            _groupCounters[nd4j::memory::MemoryType::HOST] = 0;
+            _groupCounters[nd4j::memory::MemoryType::DEVICE] = 0;
+        }
+
+        MemoryCounter* MemoryCounter::getInstance() {
+            if (_INSTANCE == 0)
+                _INSTANCE = new MemoryCounter();
+
+            return _INSTANCE;
+        }
+
+        void MemoryCounter::countIn(int deviceId, Nd4jLong numBytes) {
+            std::lock_guard<std::mutex> lock(_locker);
+            _deviceCounters[deviceId] += numBytes;
+        }
+
+        void MemoryCounter::countIn(nd4j::memory::MemoryType group, Nd4jLong numBytes) {
+            std::lock_guard<std::mutex> lock(_locker);
+            _groupCounters[group] += numBytes;
+        }
+
+        void MemoryCounter::countOut(int deviceId, Nd4jLong numBytes) {
+            std::lock_guard<std::mutex> lock(_locker);
+            _deviceCounters[deviceId] -= numBytes;
+        }
+
+        void MemoryCounter::countOut(nd4j::memory::MemoryType group, Nd4jLong numBytes) {
+            std::lock_guard<std::mutex> lock(_locker);
+            _groupCounters[group] -= numBytes;
+        }
+
+        bool MemoryCounter::validate(Nd4jLong numBytes) {
+            auto deviceId = nd4j::AffinityManager::currentDeviceId();
+            return validateDevice(deviceId, numBytes);
+        }
+
+        bool MemoryCounter::validateDevice(int deviceId, Nd4jLong numBytes) {
+            std::lock_guard<std::mutex> lock(_locker);
+            auto dLimit = _deviceLimits[deviceId];
+            if (dLimit <= 0)
+                return true;
+
+            auto dAlloc = _deviceCounters[deviceId];
+
+            return numBytes + dAlloc <= dLimit;
+        }
+
+        bool MemoryCounter::validateGroup(nd4j::memory::MemoryType group, Nd4jLong numBytes) {
+            std::lock_guard<std::mutex> lock(_locker);
+            auto gLimit = _groupLimits[group];
+            if (gLimit <= 0)
+                return true;
+
+            auto gAlloc = _groupCounters[group];
+
+            return numBytes + gAlloc <= gLimit;
+        }
+
+        Nd4jLong MemoryCounter::allocatedDevice(int deviceId) {
+            std::lock_guard<std::mutex> lock(_locker);
+            return _deviceCounters[deviceId];
+        }
+
+        Nd4jLong MemoryCounter::allocatedGroup(nd4j::memory::MemoryType group) {
+            std::lock_guard<std::mutex> lock(_locker);
+            return _groupCounters[group];
+        }
+
+        void MemoryCounter::setDeviceLimit(int deviceId, Nd4jLong numBytes) {
+            std::lock_guard<std::mutex> lock(_locker);
+            _deviceLimits[deviceId] = numBytes;
+        }
+
+        void MemoryCounter::setGroupLimit(nd4j::memory::MemoryType group, Nd4jLong numBytes) {
+            std::lock_guard<std::mutex> lock(_locker);
+            _groupLimits[group] = numBytes;
+        }
+
+        Nd4jLong MemoryCounter::deviceLimit(int deviceId) {
+            std::lock_guard<std::mutex> lock(_locker);
+            return _deviceLimits[deviceId];
+        }
+
+        Nd4jLong MemoryCounter::groupLimit(nd4j::memory::MemoryType group) {
+            std::lock_guard<std::mutex> lock(_locker);
+            return _groupLimits[group];
+        }
+
+        MemoryCounter* MemoryCounter::_INSTANCE = 0;
+    }
+}
\ No newline at end of file
diff --git a/libnd4j/include/ops/declarable/OpRegistrator.h b/libnd4j/include/ops/declarable/OpRegistrator.h
index ccec8a3c6..789b361f3 100644
--- a/libnd4j/include/ops/declarable/OpRegistrator.h
+++ b/libnd4j/include/ops/declarable/OpRegistrator.h
@@ -23,7 +23,7 @@
 
 #include <pointercast.h>
 #include <vector>
-#include <map>
+#include <unordered_map>
 #include <mutex>
 #include <ops/declarable/DeclarableOp.h>
 #include <ops/declarable/PlatformHelper.h>
diff --git a/libnd4j/include/ops/declarable/helpers/cpu/segment.cpp b/libnd4j/include/ops/declarable/helpers/cpu/segment.cpp
index 5e21e3b8e..e20145735 100644
--- a/libnd4j/include/ops/declarable/helpers/cpu/segment.cpp
+++ b/libnd4j/include/ops/declarable/helpers/cpu/segment.cpp
@@ -22,7 +22,7 @@
 #include <ops/declarable/helpers/segment.h>
 #include <ShapeUtils.h>
 #include <execution/Threads.h>
-#include <map>
+#include <unordered_map>
 
 namespace nd4j {
 namespace ops {
diff --git a/libnd4j/tests_cpu/layers_tests/DataBufferTests.cpp b/libnd4j/tests_cpu/layers_tests/DataBufferTests.cpp
new file mode 100644
index 000000000..e6d270141
--- /dev/null
+++ b/libnd4j/tests_cpu/layers_tests/DataBufferTests.cpp
@@ -0,0 +1,78 @@
+/*******************************************************************************
+ * Copyright (c) 2020 Konduit K.K.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Apache License, Version 2.0 which is available at
+ * https://www.apache.org/licenses/LICENSE-2.0.
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ ******************************************************************************/
+
+//
+// @author raver119@gmail.com
+//
+
+#include "testlayers.h"
+#include <NDArray.h>
+#include <Context.h>
+#include <Node.h>
+#include <graph/Variable.h>
+#include <graph/VariableSpace.h>
+#include <ops/declarable/CustomOperations.h>
+#include <ops/declarable/helpers/convolutions.h>
+#include <ops/declarable/helpers/col2im.h>
+#include <helpers/RandomLauncher.h>
+
+using namespace nd4j;
+using namespace nd4j::graph;
+using namespace nd4j::memory;
+
+class DataBufferTests : public testing::Test {
+public:
+
+};
+
+TEST_F(DataBufferTests, test_alloc_limit_1) {
+    if (!Environment::getInstance()->isCPU())
+        return;
+
+    auto deviceId = AffinityManager::currentDeviceId();
+    auto odLimit = MemoryCounter::getInstance()->deviceLimit(deviceId);
+    auto ogLimit = MemoryCounter::getInstance()->groupLimit(MemoryType::HOST);
+    auto odUse = MemoryCounter::getInstance()->allocatedDevice(deviceId);
+    auto ogUse = MemoryCounter::getInstance()->allocatedGroup(MemoryType::HOST);
+
+    auto limitSize = 150 * 1024 * 1024;
+    auto allocSize = 100000000;
+
+    MemoryCounter::getInstance()->setDeviceLimit(deviceId, odLimit + limitSize);
+    MemoryCounter::getInstance()->setGroupLimit(MemoryType::HOST, odLimit + limitSize);
+
+    DataBuffer buffer(allocSize, DataType::INT32);
+
+    // separately testing per-device limits and group limits
+    ASSERT_EQ(odUse + allocSize, MemoryCounter::getInstance()->allocatedDevice(deviceId));
+    ASSERT_EQ(ogUse + allocSize, MemoryCounter::getInstance()->allocatedGroup(MemoryType::HOST));
+
+
+    // setting smaller limits, to make sure next allocation fails with OOM exception
+    MemoryCounter::getInstance()->setDeviceLimit(deviceId, allocSize - 100);
+    MemoryCounter::getInstance()->setGroupLimit(MemoryType::HOST, allocSize - 100);
+
+    try {
+        DataBuffer bufferFailed(allocSize, DataType::INT32);
+        ASSERT_TRUE(false);
+    } catch (allocation_exception &e) {
+        // we expect exception here
+    }
+
+    // restore original limits, so subsequent tests do not fail
+    MemoryCounter::getInstance()->setDeviceLimit(deviceId, odLimit);
+    MemoryCounter::getInstance()->setGroupLimit(MemoryType::HOST, odLimit);
+}
\ No newline at end of file
diff --git a/libnd4j/tests_cpu/layers_tests/DataBufferTestsCuda.cu b/libnd4j/tests_cpu/layers_tests/DataBufferTestsCuda.cu
new file mode 100644
index 000000000..355633a4e
--- /dev/null
+++ b/libnd4j/tests_cpu/layers_tests/DataBufferTestsCuda.cu
@@ -0,0 +1,87 @@
+/*******************************************************************************
+ * Copyright (c) 2020 Konduit K.K.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Apache License, Version 2.0 which is available at
+ * https://www.apache.org/licenses/LICENSE-2.0.
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ ******************************************************************************/
+
+//
+// @author raver119@gmail.com
+//
+
+#include "testlayers.h"
+#include <NDArray.h>
+#include <Context.h>
+#include <Node.h>
+#include <graph/Variable.h>
+#include <graph/VariableSpace.h>
+#include <ops/declarable/CustomOperations.h>
+#include <ops/declarable/helpers/convolutions.h>
+#include <ops/declarable/helpers/col2im.h>
+#include <helpers/RandomLauncher.h>
+
+using namespace nd4j;
+using namespace nd4j::graph;
+using namespace nd4j::memory;
+
+class DataBufferTestsCuda : public testing::Test {
+public:
+
+};
+
+TEST_F(DataBufferTestsCuda, test_alloc_limit_1) {
+    auto deviceId = AffinityManager::currentDeviceId();
+
+    auto odLimit = MemoryCounter::getInstance()->deviceLimit(deviceId);
+
+    auto opLimit = MemoryCounter::getInstance()->groupLimit(MemoryType::HOST);
+    auto osLimit = MemoryCounter::getInstance()->groupLimit(MemoryType::DEVICE);
+
+    auto odUse = MemoryCounter::getInstance()->allocatedDevice(deviceId);
+
+    auto opUse = MemoryCounter::getInstance()->allocatedGroup(MemoryType::HOST);
+    auto osUse = MemoryCounter::getInstance()->allocatedGroup(MemoryType::DEVICE);
+
+    auto limitSize = 150000000;
+    auto allocSize = 100000000;
+
+    MemoryCounter::getInstance()->setDeviceLimit(deviceId, odLimit + limitSize);
+    MemoryCounter::getInstance()->setGroupLimit(MemoryType::HOST, opLimit + limitSize);
+    MemoryCounter::getInstance()->setGroupLimit(MemoryType::DEVICE, osLimit + limitSize);
+
+    DataBuffer buffer(allocSize, DataType::INT32, nullptr, true);
+
+    // separately testing per-device limits and group limits
+    ASSERT_EQ(odUse + allocSize, MemoryCounter::getInstance()->allocatedDevice(deviceId));
+    ASSERT_EQ(opUse + allocSize, MemoryCounter::getInstance()->allocatedGroup(MemoryType::HOST));
+    ASSERT_EQ(osUse + allocSize, MemoryCounter::getInstance()->allocatedGroup(MemoryType::DEVICE));
+
+    // setting smaller limits, to make sure next allocation fails with OOM exception
+    MemoryCounter::getInstance()->setDeviceLimit(deviceId, allocSize - 100);
+    MemoryCounter::getInstance()->setGroupLimit(MemoryType::DEVICE, allocSize - 100);
+
+
+    // this allocation should fail, since we're allocating too much
+    try {
+        DataBuffer bufferFailed(allocSize, DataType::INT32);
+        ASSERT_TRUE(false);
+    } catch (allocation_exception &e) {
+        // we expect exception here
+    }
+
+    //
+
+    // restore original limits, so subsequent tests do not fail
+    MemoryCounter::getInstance()->setDeviceLimit(deviceId, odLimit);
+    MemoryCounter::getInstance()->setGroupLimit(MemoryType::HOST, opLimit);
+    MemoryCounter::getInstance()->setGroupLimit(MemoryType::DEVICE, osLimit);
+}
\ No newline at end of file
diff --git a/libnd4j/tests_cpu/layers_tests/DataTypesValidationTests.cpp b/libnd4j/tests_cpu/layers_tests/DataTypesValidationTests.cpp
index b646a493d..e87dfa125 100644
--- a/libnd4j/tests_cpu/layers_tests/DataTypesValidationTests.cpp
+++ b/libnd4j/tests_cpu/layers_tests/DataTypesValidationTests.cpp
@@ -29,8 +29,6 @@
 #include <ops/declarable/helpers/col2im.h>
 #include <helpers/RandomLauncher.h>
 
-using namespace nd4j;
-
 using namespace nd4j;
 using namespace nd4j::graph;
 
diff --git a/nd4j/nd4j-backends/nd4j-api-parent/nd4j-api/src/main/java/org/nd4j/linalg/api/ops/impl/transforms/pairwise/arithmetic/RSubOp.java b/nd4j/nd4j-backends/nd4j-api-parent/nd4j-api/src/main/java/org/nd4j/linalg/api/ops/impl/transforms/pairwise/arithmetic/RSubOp.java
index f6cf14bd4..b0090d047 100644
--- a/nd4j/nd4j-backends/nd4j-api-parent/nd4j-api/src/main/java/org/nd4j/linalg/api/ops/impl/transforms/pairwise/arithmetic/RSubOp.java
+++ b/nd4j/nd4j-backends/nd4j-api-parent/nd4j-api/src/main/java/org/nd4j/linalg/api/ops/impl/transforms/pairwise/arithmetic/RSubOp.java
@@ -63,7 +63,7 @@ public class RSubOp extends BaseDynamicTransformOp {
 
     @Override
     public String tensorflowName() {
-        return "Sub";
+        throw new NoOpNameFoundException("No TensorFlow op name found for: " + getClass().getName());
     }
 
     public RSubOp( INDArray[] inputs, INDArray[] outputs) {
diff --git a/nd4j/nd4j-backends/nd4j-api-parent/nd4j-native-api/src/main/java/org/nd4j/nativeblas/OpaqueDataBuffer.java b/nd4j/nd4j-backends/nd4j-api-parent/nd4j-native-api/src/main/java/org/nd4j/nativeblas/OpaqueDataBuffer.java
index 3fb5d2748..d5a84eac3 100644
--- a/nd4j/nd4j-backends/nd4j-api-parent/nd4j-native-api/src/main/java/org/nd4j/nativeblas/OpaqueDataBuffer.java
+++ b/nd4j/nd4j-backends/nd4j-api-parent/nd4j-native-api/src/main/java/org/nd4j/nativeblas/OpaqueDataBuffer.java
@@ -18,18 +18,23 @@
 package org.nd4j.nativeblas;
 
 import lombok.NonNull;
+import lombok.extern.slf4j.Slf4j;
 import lombok.val;
 import org.bytedeco.javacpp.Pointer;
 import org.nd4j.linalg.api.buffer.DataType;
 
+import java.util.concurrent.locks.LockSupport;
+
 /**
  * This class is a opaque pointer to InteropDataBuffer, used for Java/C++ interop related to INDArray DataBuffer
  *
  * @author saudet
+ * @author raver119@gmail.com
  */
+@Slf4j
 public class OpaqueDataBuffer extends Pointer {
     // TODO: make this configurable
-    private static final int MAX_TRIES = 3;
+    private static final int MAX_TRIES = 5;
 
     public OpaqueDataBuffer(Pointer p) { super(p); }
 
@@ -53,11 +58,13 @@ public class OpaqueDataBuffer extends Pointer {
                 // check error code
                 ec = NativeOpsHolder.getInstance().getDeviceNativeOps().lastErrorCode();
                 if (ec != 0) {
-                    if (em == null)
-                        em = NativeOpsHolder.getInstance().getDeviceNativeOps().lastErrorMessage();
+                    em = NativeOpsHolder.getInstance().getDeviceNativeOps().lastErrorMessage();
 
                     // if allocation failed it might be caused by casual OOM, so we'll try GC
                     System.gc();
+
+                    // sleeping for 50ms
+                    Thread.sleep(50);
                 } else {
                     // just return the buffer
                     return buffer;
@@ -89,11 +96,12 @@ public class OpaqueDataBuffer extends Pointer {
                 // check error code
                 ec = NativeOpsHolder.getInstance().getDeviceNativeOps().lastErrorCode();
                 if (ec != 0) {
-                    if (em == null)
-                        em = NativeOpsHolder.getInstance().getDeviceNativeOps().lastErrorMessage();
+                    em = NativeOpsHolder.getInstance().getDeviceNativeOps().lastErrorMessage();
 
                     // if expansion failed it might be caused by casual OOM, so we'll try GC
                     System.gc();
+
+                    Thread.sleep(50);
                 } else {
                     // just return
                     return;
@@ -126,11 +134,13 @@ public class OpaqueDataBuffer extends Pointer {
                 // check error code
                 ec = NativeOpsHolder.getInstance().getDeviceNativeOps().lastErrorCode();
                 if (ec != 0) {
-                    if (em == null)
-                        em = NativeOpsHolder.getInstance().getDeviceNativeOps().lastErrorMessage();
+                    em = NativeOpsHolder.getInstance().getDeviceNativeOps().lastErrorMessage();
 
                     // if view creation failed it might be caused by casual OOM, so we'll try GC
                     System.gc();
+
+                    // sleeping to let gc kick in
+                    Thread.sleep(50);
                 } else {
                     // just return
                     return buffer;
diff --git a/nd4j/nd4j-backends/nd4j-backend-impls/nd4j-cuda/src/main/java/org/nd4j/nativeblas/CudaEnvironment.java b/nd4j/nd4j-backends/nd4j-backend-impls/nd4j-cuda/src/main/java/org/nd4j/nativeblas/CudaEnvironment.java
index 83e9c156f..16abeef9a 100644
--- a/nd4j/nd4j-backends/nd4j-backend-impls/nd4j-cuda/src/main/java/org/nd4j/nativeblas/CudaEnvironment.java
+++ b/nd4j/nd4j-backends/nd4j-backend-impls/nd4j-cuda/src/main/java/org/nd4j/nativeblas/CudaEnvironment.java
@@ -167,4 +167,29 @@ public class CudaEnvironment implements Environment {
     public boolean isCPU() {
         return e.isCPU();
     }
+
+    @Override
+    public void setGroupLimit(int group, long numBytes) {
+        e.setGroupLimit(group, numBytes);
+    }
+
+    @Override
+    public void setDeviceLimit(int deviceId, long numBytes) {
+        e.setDeviceLimit(deviceId, numBytes);
+    }
+
+    @Override
+    public long getGroupLimit(int group) {
+        return e.getGroupLimit(group);
+    }
+
+    @Override
+    public long getDeviceLimit(int deviceId) {
+        return e.getDeviceLimit(deviceId);
+    }
+
+    @Override
+    public long getDeviceCouner(int deviceId) {
+        return e.getDeviceCounter(deviceId);
+    }
 }
diff --git a/nd4j/nd4j-backends/nd4j-backend-impls/nd4j-cuda/src/main/java/org/nd4j/nativeblas/Nd4jCuda.java b/nd4j/nd4j-backends/nd4j-backend-impls/nd4j-cuda/src/main/java/org/nd4j/nativeblas/Nd4jCuda.java
index b98630dc4..5aa685c7a 100644
--- a/nd4j/nd4j-backends/nd4j-backend-impls/nd4j-cuda/src/main/java/org/nd4j/nativeblas/Nd4jCuda.java
+++ b/nd4j/nd4j-backends/nd4j-backend-impls/nd4j-cuda/src/main/java/org/nd4j/nativeblas/Nd4jCuda.java
@@ -495,7 +495,7 @@ public class Nd4jCuda extends org.nd4j.nativeblas.Nd4jCudaHelper {
 // #define DEV_TESTS_CONSTANTDESCRIPTOR_H
 
 // #include <array/DataType.h>
-// #include <map>
+// #include <unordered_map>
 // #include <vector>
 // #include <pointercast.h>
 // #include <dll.h>
@@ -808,6 +808,7 @@ public class Nd4jCuda extends org.nd4j.nativeblas.Nd4jCudaHelper {
 // #include <stdexcept>
 // #include <array/DataType.h>
 // #include <types/pair.h>
+// #include <pointercast.h>
     @Namespace("nd4j") @NoOffset public static class Environment extends Pointer {
         static { Loader.load(); }
         /** Pointer cast constructor. Invokes {@link Pointer#Pointer(Pointer)}. */
@@ -846,10 +847,30 @@ public class Nd4jCuda extends org.nd4j.nativeblas.Nd4jCudaHelper {
         public native int maxMasterThreads();
         public native void setMaxMasterThreads(int max);
 
+        /*
+         * Legacy memory limits API, still used in new API as simplified version
+         */
         public native void setMaxPrimaryMemory(@Cast("uint64_t") long maxBytes);
         public native void setMaxSpecialyMemory(@Cast("uint64_t") long maxBytes);
         public native void setMaxDeviceMemory(@Cast("uint64_t") long maxBytes);
 
+        public native @Cast("uint64_t") long maxPrimaryMemory();
+        public native @Cast("uint64_t") long maxSpecialMemory();
+        ////////////////////////
+
+        /*
+         * Methods for memory limits/counters
+         */
+        public native void setGroupLimit(int group, @Cast("Nd4jLong") long numBytes);
+        public native void setDeviceLimit(int deviceId, @Cast("Nd4jLong") long numBytes);
+
+        public native @Cast("Nd4jLong") long getGroupLimit(int group);
+        public native @Cast("Nd4jLong") long getDeviceLimit(int deviceId);
+
+        public native @Cast("Nd4jLong") long getGroupCounter(int group);
+        public native @Cast("Nd4jLong") long getDeviceCounter(int deviceId);
+        ////////////////////////
+
         public native @Cast("bool") boolean isUseMKLDNN();
         public native void setUseMKLDNN(@Cast("bool") boolean useMKLDNN);
 
@@ -1017,6 +1038,7 @@ bool verbose = false;
 // #include <graph/execution/LogicExecutor.h>
 // #include <graph/ResultWrapper.h>
 // #include <DebugInfo.h>
+// #include <memory/MemoryCounter.h>
 
 /**
  * This function returns last error code stored,
@@ -3591,6 +3613,7 @@ public native @Cast("bool") boolean isOptimalRequirementsMet();
 // #include <execution/AffinityManager.h>
 // #include <memory>
 // #include <array/InteropDataBuffer.h>
+// #include <memory/MemoryCounter.h>
 
 
 
@@ -4856,7 +4879,7 @@ public native @Cast("bool") boolean isOptimalRequirementsMet();
 
 // #include <string>
 // #include <atomic>
-// #include <map>
+// #include <unordered_map>
 // #include <NDArray.h>
 // #include <memory/Workspace.h>
 // #include <dll.h>
@@ -5007,6 +5030,7 @@ public native @Cast("bool") boolean isOptimalRequirementsMet();
 // #include <chrono>
 // #include <array/DataTypeUtils.h>
 // #include <helpers/logger.h>
+// #include <stdexcept>
 
 // #ifdef __CUDACC__
 // #endif
@@ -5458,7 +5482,7 @@ public native @Cast("bool") boolean isOptimalRequirementsMet();
 
 //#include <graph/Block.h>
 // #include <NDArray.h>
-// #include <map>
+// #include <unordered_map>
 // #include <string>
 // #include <atomic>
 // #include <pointercast.h>
@@ -5549,7 +5573,7 @@ public native @Cast("bool") boolean isOptimalRequirementsMet();
 // #include <op_boilerplate.h>
 // #include <dll.h>
 // #include <vector>
-// #include <map>
+// #include <unordered_map>
 // #include <graph/Scope.h>
 // #include <Status.h>
 // #include <graph/VariableSpace.h>
@@ -5665,7 +5689,7 @@ public native @Cast("bool") boolean isOptimalRequirementsMet();
 // #include <string>
 // #include <vector>
 // #include <list>
-// #include <map>
+// #include <unordered_map>
 // #include <mutex>
 // #include <NDArray.h>
 // #include <array/NDArrayList.h>
@@ -9674,7 +9698,7 @@ public static final int PREALLOC_SIZE = 33554432;
 
 // #include <pointercast.h>
 // #include <vector>
-// #include <map>
+// #include <unordered_map>
 // #include <mutex>
 // #include <ops/declarable/DeclarableOp.h>
 // #include <ops/declarable/PlatformHelper.h>
@@ -9939,7 +9963,7 @@ public static final int PREALLOC_SIZE = 33554432;
 // #ifndef DEV_TESTS_SHAPEDESCRIPTOR_H
 // #define DEV_TESTS_SHAPEDESCRIPTOR_H
 
-// #include <map>
+// #include <unordered_map>
 // #include <vector>
 // #include <dll.h>
 // #include <pointercast.h>
diff --git a/nd4j/nd4j-backends/nd4j-backend-impls/nd4j-native/src/main/java/org/nd4j/linalg/cpu/nativecpu/CpuEnvironment.java b/nd4j/nd4j-backends/nd4j-backend-impls/nd4j-native/src/main/java/org/nd4j/linalg/cpu/nativecpu/CpuEnvironment.java
index a97b52d9f..363e8857b 100644
--- a/nd4j/nd4j-backends/nd4j-backend-impls/nd4j-native/src/main/java/org/nd4j/linalg/cpu/nativecpu/CpuEnvironment.java
+++ b/nd4j/nd4j-backends/nd4j-backend-impls/nd4j-native/src/main/java/org/nd4j/linalg/cpu/nativecpu/CpuEnvironment.java
@@ -167,4 +167,29 @@ public class CpuEnvironment implements Environment {
     public boolean isCPU() {
         return e.isCPU();
     }
+
+    @Override
+    public void setGroupLimit(int group, long numBytes) {
+        e.setGroupLimit(group, numBytes);
+    }
+
+    @Override
+    public void setDeviceLimit(int deviceId, long numBytes) {
+        e.setDeviceLimit(deviceId, numBytes);
+    }
+
+    @Override
+    public long getGroupLimit(int group) {
+        return e.getGroupLimit(group);
+    }
+
+    @Override
+    public long getDeviceLimit(int deviceId) {
+        return e.getDeviceLimit(deviceId);
+    }
+
+    @Override
+    public long getDeviceCouner(int deviceId) {
+        return e.getDeviceCounter(deviceId);
+    }
 }
diff --git a/nd4j/nd4j-backends/nd4j-backend-impls/nd4j-native/src/main/java/org/nd4j/nativeblas/Nd4jCpu.java b/nd4j/nd4j-backends/nd4j-backend-impls/nd4j-native/src/main/java/org/nd4j/nativeblas/Nd4jCpu.java
index 784386cc8..cfabc651c 100644
--- a/nd4j/nd4j-backends/nd4j-backend-impls/nd4j-native/src/main/java/org/nd4j/nativeblas/Nd4jCpu.java
+++ b/nd4j/nd4j-backends/nd4j-backend-impls/nd4j-native/src/main/java/org/nd4j/nativeblas/Nd4jCpu.java
@@ -573,7 +573,7 @@ public class Nd4jCpu extends org.nd4j.nativeblas.Nd4jCpuHelper {
 // #define DEV_TESTS_CONSTANTDESCRIPTOR_H
 
 // #include <array/DataType.h>
-// #include <map>
+// #include <unordered_map>
 // #include <vector>
 // #include <pointercast.h>
 // #include <dll.h>
@@ -811,6 +811,7 @@ public class Nd4jCpu extends org.nd4j.nativeblas.Nd4jCpuHelper {
 // #include <stdexcept>
 // #include <array/DataType.h>
 // #include <types/pair.h>
+// #include <pointercast.h>
     @Namespace("nd4j") @NoOffset public static class Environment extends Pointer {
         static { Loader.load(); }
         /** Pointer cast constructor. Invokes {@link Pointer#Pointer(Pointer)}. */
@@ -849,10 +850,30 @@ public class Nd4jCpu extends org.nd4j.nativeblas.Nd4jCpuHelper {
         public native int maxMasterThreads();
         public native void setMaxMasterThreads(int max);
 
+        /*
+         * Legacy memory limits API, still used in new API as simplified version
+         */
         public native void setMaxPrimaryMemory(@Cast("uint64_t") long maxBytes);
         public native void setMaxSpecialyMemory(@Cast("uint64_t") long maxBytes);
         public native void setMaxDeviceMemory(@Cast("uint64_t") long maxBytes);
 
+        public native @Cast("uint64_t") long maxPrimaryMemory();
+        public native @Cast("uint64_t") long maxSpecialMemory();
+        ////////////////////////
+
+        /*
+         * Methods for memory limits/counters
+         */
+        public native void setGroupLimit(int group, @Cast("Nd4jLong") long numBytes);
+        public native void setDeviceLimit(int deviceId, @Cast("Nd4jLong") long numBytes);
+
+        public native @Cast("Nd4jLong") long getGroupLimit(int group);
+        public native @Cast("Nd4jLong") long getDeviceLimit(int deviceId);
+
+        public native @Cast("Nd4jLong") long getGroupCounter(int group);
+        public native @Cast("Nd4jLong") long getDeviceCounter(int deviceId);
+        ////////////////////////
+
         public native @Cast("bool") boolean isUseMKLDNN();
         public native void setUseMKLDNN(@Cast("bool") boolean useMKLDNN);
 
@@ -1020,6 +1041,7 @@ bool verbose = false;
 // #include <graph/execution/LogicExecutor.h>
 // #include <graph/ResultWrapper.h>
 // #include <DebugInfo.h>
+// #include <memory/MemoryCounter.h>
 
 /**
  * This function returns last error code stored,
@@ -3594,6 +3616,7 @@ public native @Cast("bool") boolean isOptimalRequirementsMet();
 // #include <execution/AffinityManager.h>
 // #include <memory>
 // #include <array/InteropDataBuffer.h>
+// #include <memory/MemoryCounter.h>
 
 
 
@@ -4859,7 +4882,7 @@ public native @Cast("bool") boolean isOptimalRequirementsMet();
 
 // #include <string>
 // #include <atomic>
-// #include <map>
+// #include <unordered_map>
 // #include <NDArray.h>
 // #include <memory/Workspace.h>
 // #include <dll.h>
@@ -5010,6 +5033,7 @@ public native @Cast("bool") boolean isOptimalRequirementsMet();
 // #include <chrono>
 // #include <array/DataTypeUtils.h>
 // #include <helpers/logger.h>
+// #include <stdexcept>
 
 // #ifdef __CUDACC__
 // #endif
@@ -5461,7 +5485,7 @@ public native @Cast("bool") boolean isOptimalRequirementsMet();
 
 //#include <graph/Block.h>
 // #include <NDArray.h>
-// #include <map>
+// #include <unordered_map>
 // #include <string>
 // #include <atomic>
 // #include <pointercast.h>
@@ -5552,7 +5576,7 @@ public native @Cast("bool") boolean isOptimalRequirementsMet();
 // #include <op_boilerplate.h>
 // #include <dll.h>
 // #include <vector>
-// #include <map>
+// #include <unordered_map>
 // #include <graph/Scope.h>
 // #include <Status.h>
 // #include <graph/VariableSpace.h>
@@ -5668,7 +5692,7 @@ public native @Cast("bool") boolean isOptimalRequirementsMet();
 // #include <string>
 // #include <vector>
 // #include <list>
-// #include <map>
+// #include <unordered_map>
 // #include <mutex>
 // #include <NDArray.h>
 // #include <array/NDArrayList.h>
@@ -11885,7 +11909,7 @@ public static final int TAD_THRESHOLD = TAD_THRESHOLD();
 
 // #include <pointercast.h>
 // #include <vector>
-// #include <map>
+// #include <unordered_map>
 // #include <mutex>
 // #include <ops/declarable/DeclarableOp.h>
 // #include <ops/declarable/PlatformHelper.h>
@@ -17106,6 +17130,7 @@ public static final int TAD_THRESHOLD = TAD_THRESHOLD();
          * Input : batched tensor with rank >=2
          * Output: tensor with rank lesser by 1 from input
          */
+//         #if NOT_EXCLUDED(OP_matrix_diag_part)
         @Namespace("nd4j::ops") public static class matrix_diag_part extends DeclarableCustomOp {
             static { Loader.load(); }
             /** Pointer cast constructor. Invokes {@link Pointer#Pointer(Pointer)}. */
@@ -17121,7 +17146,36 @@ public static final int TAD_THRESHOLD = TAD_THRESHOLD();
                                                                                     private native void allocate();
                                                                                     public native ShapeList calculateOutputShape(ShapeList inputShape, @ByRef Context block);
                                                                                 }
+//         #endif
 
+        /**
+         * QR decomposition: A = QR, where Q is ortogonal (Q * QT = I) and R is upper triangular.
+         * For A (MxN) Q is M x M and R is (NxN). 
+         *
+         * Input : 
+         *    0 - float (or complex float) tensor with shape {.,..,...,M,N} - batch of float matricies
+         *
+         * Output: 
+         *    0 - float tensor with shape {.,..,...,MxN} - batch of ortogonal matricies {Qs}
+         *    1 - float tensor with shape {.,..,...,NxN} - batch of upper triangular matricies {Rs}
+         */
+//         #if NOT_EXCLUDED(OP_qr)
+        @Namespace("nd4j::ops") public static class qr extends DeclarableCustomOp {
+            static { Loader.load(); }
+            /** Pointer cast constructor. Invokes {@link Pointer#Pointer(Pointer)}. */
+            public qr(Pointer p) { super(p); }
+            /** Native array allocator. Access with {@link Pointer#position(long)}. */
+            public qr(long size) { super((Pointer)null); allocateArray(size); }
+            private native void allocateArray(long size);
+            @Override public qr position(long position) {
+                return (qr)super.position(position);
+            }
+        
+                                                                                    public qr() { super((Pointer)null); allocate(); }
+                                                                                    private native void allocate();
+                                                                                    public native ShapeList calculateOutputShape(ShapeList inputShape, @ByRef Context block);
+                                                                                }
+//         #endif
 
         /**
          * This operation takes 2 arrays: original values, and values to be excluded. And returns 2 arrays: values left after exclusion, and indices in original array for surivals.
@@ -23687,7 +23741,7 @@ public static final int TAD_THRESHOLD = TAD_THRESHOLD();
 // #ifndef DEV_TESTS_SHAPEDESCRIPTOR_H
 // #define DEV_TESTS_SHAPEDESCRIPTOR_H
 
-// #include <map>
+// #include <unordered_map>
 // #include <vector>
 // #include <dll.h>
 // #include <pointercast.h>
diff --git a/nd4j/nd4j-backends/nd4j-tests/src/test/java/org/nd4j/linalg/Nd4jTestsC.java b/nd4j/nd4j-backends/nd4j-tests/src/test/java/org/nd4j/linalg/Nd4jTestsC.java
index c86246a52..ce1ad388c 100644
--- a/nd4j/nd4j-backends/nd4j-tests/src/test/java/org/nd4j/linalg/Nd4jTestsC.java
+++ b/nd4j/nd4j-backends/nd4j-tests/src/test/java/org/nd4j/linalg/Nd4jTestsC.java
@@ -459,7 +459,7 @@ public class Nd4jTestsC extends BaseNd4jTest {
     @Test
     public void testSubiRowVector() {
         INDArray oneThroughFour = Nd4j.linspace(1, 4, 4, DataType.DOUBLE).reshape('c', 2, 2);
-        INDArray row1 = oneThroughFour.getRow(1);
+        INDArray row1 = oneThroughFour.getRow(1).dup();
         oneThroughFour.subiRowVector(row1);
         INDArray result = Nd4j.create(new double[] {-2, -2, 0, 0}, new long[] {2, 2});
         assertEquals(getFailureMessage(), result, oneThroughFour);
diff --git a/nd4j/nd4j-backends/nd4j-tests/src/test/java/org/nd4j/linalg/api/TestNDArrayCreation.java b/nd4j/nd4j-backends/nd4j-tests/src/test/java/org/nd4j/linalg/api/TestNDArrayCreation.java
index cea64a90b..85126b306 100644
--- a/nd4j/nd4j-backends/nd4j-tests/src/test/java/org/nd4j/linalg/api/TestNDArrayCreation.java
+++ b/nd4j/nd4j-backends/nd4j-tests/src/test/java/org/nd4j/linalg/api/TestNDArrayCreation.java
@@ -17,6 +17,7 @@
 package org.nd4j.linalg.api;
 
 import lombok.extern.slf4j.Slf4j;
+import lombok.val;
 import org.bytedeco.javacpp.FloatPointer;
 import org.bytedeco.javacpp.Pointer;
 import org.junit.Ignore;
@@ -32,7 +33,7 @@ import org.nd4j.nativeblas.NativeOpsHolder;
 
 import java.util.Map;
 
-import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.*;
 
 /**
  * Created by Alex on 30/04/2016.
@@ -109,6 +110,44 @@ public class TestNDArrayCreation extends BaseNd4jTest {
         assertEquals(arrCreate.data().address(), pointer.address());
     }
 
+    @Test
+    @Ignore // this is endless test
+    public void testEndlessAllocation() {
+        Nd4j.getEnvironment().setMaxSpecialMemory(1);
+        while (true) {
+            val arr = Nd4j.createUninitialized(DataType.FLOAT, 100000000);
+            arr.assign(1.0f);
+        }
+    }
+
+    @Test
+    @Ignore("This test is designed to run in isolation. With parallel gc it makes no real sense since allocated amount changes at any time")
+    public void testAllocationLimits() throws Exception {
+        Nd4j.create(1);
+
+        val origDeviceLimit = Nd4j.getEnvironment().getDeviceLimit(0);
+        val origDeviceCount = Nd4j.getEnvironment().getDeviceCouner(0);
+
+        val limit = origDeviceCount + 10000;
+
+        Nd4j.getEnvironment().setDeviceLimit(0, limit);
+
+        val array = Nd4j.createUninitialized(DataType.DOUBLE, 1024);
+        assertNotNull(array);
+
+        try {
+            Nd4j.createUninitialized(DataType.DOUBLE, 1024);
+            assertTrue(false);
+        } catch (Exception e) {
+            //
+        }
+
+        // we want to be sure there's nothing left after exception
+        assertEquals(0, NativeOpsHolder.getInstance().getDeviceNativeOps().lastErrorCode());
+
+        Nd4j.getEnvironment().setDeviceLimit(0, origDeviceLimit);
+
+    }
 
     @Override
     public char ordering() {
diff --git a/nd4j/nd4j-context/src/main/java/org/nd4j/linalg/factory/Environment.java b/nd4j/nd4j-context/src/main/java/org/nd4j/linalg/factory/Environment.java
index ce8e7e9f6..1b788220a 100644
--- a/nd4j/nd4j-context/src/main/java/org/nd4j/linalg/factory/Environment.java
+++ b/nd4j/nd4j-context/src/main/java/org/nd4j/linalg/factory/Environment.java
@@ -82,4 +82,39 @@ public interface Environment {
 
     /** Return true if the backend is a CPU backend, or false otherwise */
     boolean isCPU();
+
+    /**
+     * This method allows to set memory limit for a specific group of devices. I.e. CUDA or CPU
+     * @param group
+     * @param numBytes
+     */
+    void setGroupLimit(int group, long numBytes);
+
+    /**
+     * This method allows to set memory limit for a specific device. I.e. GPU_0
+     * @param deviceId
+     * @param numBytes
+     */
+    void setDeviceLimit(int deviceId, long numBytes);
+
+    /**
+     * This method returns current group limit
+     * @param group
+     * @return
+     */
+    long getGroupLimit(int group);
+
+    /**
+     * This method returns current device limit
+     * @param deviceId
+     * @return
+     */
+    long getDeviceLimit(int deviceId);
+
+    /**
+     * This method returns current allocated amount for a specific device. I.e. GPU_0
+     * @param deviceId
+     * @return
+     */
+    long getDeviceCouner(int deviceId);
 }