diff --git a/VERSION b/VERSION
index 1a1fb46b0d8..e6387dd184c 100644
--- a/VERSION
+++ b/VERSION
@@ -1,8 +1,8 @@
 MAJOR = 2
 MINOR = 3
-PATCH = 0-rc3
+PATCH = 0
 # A specific DATE (YYYY-MM-DD) fixes an official release, otherwise
 # it is considered Development version.
-DATE  = 2022-06-08
+DATE  = 2022-06-26
 
 
diff --git a/src/acc/libsmm_acc/notebooks/requirements.txt b/src/acc/libsmm_acc/notebooks/requirements.txt
index 7549e6ca84d..f36ef7a07a0 100644
--- a/src/acc/libsmm_acc/notebooks/requirements.txt
+++ b/src/acc/libsmm_acc/notebooks/requirements.txt
@@ -1,6 +1,6 @@
 bokeh==1.0.4
 matplotlib==3.0.2
-numpy==1.21.0
+numpy==1.22.0
 pandas==0.23.4
 pandas-profiling==1.4.1
 seaborn==0.9.0
diff --git a/src/acc/libsmm_acc/tune/requirements.txt b/src/acc/libsmm_acc/tune/requirements.txt
index 819f6377b80..23641586c2d 100644
--- a/src/acc/libsmm_acc/tune/requirements.txt
+++ b/src/acc/libsmm_acc/tune/requirements.txt
@@ -1 +1 @@
-numpy==1.21.0
+numpy==1.22.0
diff --git a/src/acc/opencl/acc_opencl.c b/src/acc/opencl/acc_opencl.c
index 3d79cba97cd..53dda0e2c06 100644
--- a/src/acc/opencl/acc_opencl.c
+++ b/src/acc/opencl/acc_opencl.c
@@ -217,7 +217,7 @@ int c_dbcsr_acc_init(void) {
     char buffer[ACC_OPENCL_BUFFERSIZE];
     const char *const env_devmatch = getenv("ACC_OPENCL_DEVMATCH"), *const env_devtype = getenv("ACC_OPENCL_DEVTYPE");
     const char *const env_priority = getenv("ACC_OPENCL_PRIORITY"), *const env_xhints = getenv("ACC_OPENCL_XHINTS");
-    const char *const env_nullify = getenv("ACC_OPENCL_NULLIFY"), *const env_dump_acc = getenv("ACC_OPENCL_DUMP");
+    const char *const env_devcopy = getenv("ACC_OPENCL_DEVCOPY"), *const env_dump_acc = getenv("ACC_OPENCL_DUMP");
     const char *const env_verbose = getenv("ACC_OPENCL_VERBOSE"), *const env_flush = getenv("ACC_OPENCL_FLUSH");
     const char *const env_device = getenv("ACC_OPENCL_DEVICE"), *const env_timer = getenv("ACC_OPENCL_TIMER");
     const char *const env_share = getenv("ACC_OPENCL_SHARE"), *const env_async = getenv("ACC_OPENCL_ASYNC");
@@ -233,7 +233,7 @@ int c_dbcsr_acc_init(void) {
 #  endif
     c_dbcsr_acc_opencl_config.verbosity = (NULL == env_verbose ? 0 : atoi(env_verbose));
     c_dbcsr_acc_opencl_config.priority = (NULL == env_priority ? /*default*/ 3 : atoi(env_priority));
-    c_dbcsr_acc_opencl_config.nullify = (NULL == env_nullify ? /*default*/ 0 : atoi(env_nullify));
+    c_dbcsr_acc_opencl_config.devcopy = (NULL == env_devcopy ? /*default*/ 0 : atoi(env_devcopy));
     c_dbcsr_acc_opencl_config.xhints = (NULL == env_xhints ? /*default*/ 1 : atoi(env_xhints));
     c_dbcsr_acc_opencl_config.share = (NULL == env_share ? /*default*/ 0 : atoi(env_share));
     c_dbcsr_acc_opencl_config.async = (NULL == env_async ? /*default*/ 3 : atoi(env_async));
@@ -557,7 +557,7 @@ int c_dbcsr_acc_finalize(void) {
     for (i = 0; i < ACC_OPENCL_DEVICES_MAXCOUNT; ++i) {
       const cl_device_id device_id = c_dbcsr_acc_opencl_config.devices[i];
       if (NULL != device_id) {
-#  if defined(CL_VERSION_1_2)
+#  if defined(CL_VERSION_1_2) && defined(_DEBUG)
         ACC_OPENCL_CHECK(clReleaseDevice(device_id), "release device", result);
 #  endif
         /* c_dbcsr_acc_opencl_create_context scans for non-NULL devices */
diff --git a/src/acc/opencl/acc_opencl.h b/src/acc/opencl/acc_opencl.h
index 021f80ce24c..0df7f790078 100644
--- a/src/acc/opencl/acc_opencl.h
+++ b/src/acc/opencl/acc_opencl.h
@@ -223,8 +223,8 @@ typedef struct c_dbcsr_acc_opencl_config_t {
   cl_int nthreads;
   /** How to apply/use stream priorities. */
   cl_int priority;
-  /** How to zero device-side buffers. */
-  cl_int nullify;
+  /** How to zero/copy device-side buffers. */
+  cl_int devcopy;
   /** Execution-hints (command stream). */
   cl_int xhints;
   /** Share streams across threads. */
diff --git a/src/acc/opencl/acc_opencl_mem.c b/src/acc/opencl/acc_opencl_mem.c
index 373480274f4..c2c6c6c5898 100644
--- a/src/acc/opencl/acc_opencl_mem.c
+++ b/src/acc/opencl/acc_opencl_mem.c
@@ -224,7 +224,9 @@ int c_dbcsr_acc_dev_mem_allocate(void** dev_mem, size_t nbytes) {
 #    endif
       clReleaseMemObject(buffer);
 #    if defined(CL_VERSION_2_0)
-      /*if (NULL != ptr)*/ clSVMFree(context, ptr);
+      if (0 != c_dbcsr_acc_opencl_config.device[tid].svm_interop /*&& (NULL != ptr)*/) {
+        clSVMFree(context, ptr);
+      }
 #    endif
       result = EXIT_FAILURE;
     }
@@ -271,8 +273,10 @@ int c_dbcsr_acc_dev_mem_deallocate(void* dev_mem) {
     }
 #  endif
 #  if defined(CL_VERSION_2_0)
-    assert(NULL != c_dbcsr_acc_opencl_config.device[tid].context);
-    clSVMFree(c_dbcsr_acc_opencl_config.device[tid].context, ptr); /*if (NULL != ptr)*/
+    if (0 != c_dbcsr_acc_opencl_config.device[tid].svm_interop /*&& (NULL != ptr)*/) {
+      assert(NULL != c_dbcsr_acc_opencl_config.device[tid].context);
+      clSVMFree(c_dbcsr_acc_opencl_config.device[tid].context, ptr);
+    }
 #  endif
   }
 #  if defined(__DBCSR_ACC) && defined(ACC_OPENCL_PROFILE)
@@ -363,8 +367,36 @@ int c_dbcsr_acc_memcpy_d2d(const void* devmem_src, void* devmem_dst, size_t nbyt
 #  endif
   assert((NULL != devmem_src || 0 == nbytes) && (NULL != devmem_dst || 0 == nbytes) && NULL != stream);
   if (NULL != devmem_src && NULL != devmem_dst && 0 != nbytes) {
-    result = clEnqueueCopyBuffer(*ACC_OPENCL_STREAM(stream), *ACC_OPENCL_MEM(devmem_src), *ACC_OPENCL_MEM(devmem_dst),
-      0 /*src_offset*/, 0 /*dst_offset*/, nbytes, 0, NULL, NULL);
+    const cl_mem *const src = ACC_OPENCL_MEM(devmem_src), *const dst = ACC_OPENCL_MEM(devmem_dst);
+    assert(NULL != *src && NULL != *dst);
+    if (*src != *dst) {
+      const cl_command_queue queue = *ACC_OPENCL_STREAM(stream);
+      if (0 == (2 & c_dbcsr_acc_opencl_config.devcopy)) {
+        result = clEnqueueCopyBuffer(queue, *src, *dst, 0 /*src_offset*/, 0 /*dst_offset*/, nbytes, 0, NULL, NULL);
+      }
+      else {
+        static volatile int lock; /* creating cl_kernel and clSetKernelArg must be synchronized */
+        static cl_kernel kernel = NULL;
+        LIBXSMM_ATOMIC_ACQUIRE(&lock, LIBXSMM_SYNC_NPAUSE, LIBXSMM_ATOMIC_RELAXED);
+        if (NULL == kernel) { /* generate kernel */
+          const char source[] = "kernel void memcpy_d2d(global uchar *restrict src, global uchar *restrict dst) {\n"
+                                "  const size_t i = get_global_id(0);\n"
+                                "  dst[i] = src[i];\n"
+                                "}\n";
+          result = c_dbcsr_acc_opencl_kernel(source, "memcpy_d2d" /*kernel_name*/, NULL /*build_params*/, NULL /*build_options*/,
+            NULL /*try_build_options*/, NULL /*try_ok*/, NULL /*extnames*/, 0 /*num_exts*/, &kernel);
+        }
+        if (EXIT_SUCCESS == result) {
+          assert(NULL != kernel);
+          ACC_OPENCL_CHECK(clSetKernelArg(kernel, 0, sizeof(cl_mem), src), "set src argument of memcpy_d2d kernel", result);
+          ACC_OPENCL_CHECK(clSetKernelArg(kernel, 1, sizeof(cl_mem), dst), "set dst argument of memcpy_d2d kernel", result);
+          ACC_OPENCL_CHECK(clEnqueueNDRangeKernel(
+                             queue, kernel, 1 /*work_dim*/, NULL /*offset*/, &nbytes, NULL /*local_work_size*/, 0, NULL, NULL),
+            "launch memcpy_d2d kernel", result);
+        }
+        LIBXSMM_ATOMIC_RELEASE(&lock, LIBXSMM_ATOMIC_RELAXED);
+      }
+    }
   }
 #  if defined(__DBCSR_ACC) && defined(ACC_OPENCL_PROFILE)
   c_dbcsr_timestop(&routine_handle);
@@ -385,7 +417,7 @@ int c_dbcsr_acc_memset_zero(void* dev_mem, size_t offset, size_t nbytes, void* s
   if (0 != nbytes) {
     const cl_command_queue queue = *ACC_OPENCL_STREAM(stream);
     const cl_mem* const buffer = ACC_OPENCL_MEM(dev_mem);
-    if (0 == c_dbcsr_acc_opencl_config.nullify) {
+    if (0 == (1 & c_dbcsr_acc_opencl_config.devcopy)) {
       static const cl_uchar pattern = 0; /* fill with zeros */
       result = clEnqueueFillBuffer(queue, *buffer, &pattern, sizeof(pattern), offset, nbytes, 0, NULL, NULL);
     }
diff --git a/src/acc/opencl/smm/opencl_libsmm.c b/src/acc/opencl/smm/opencl_libsmm.c
index f1fa28106eb..1428e50aa8f 100644
--- a/src/acc/opencl/smm/opencl_libsmm.c
+++ b/src/acc/opencl/smm/opencl_libsmm.c
@@ -891,8 +891,8 @@ int libsmm_acc_transpose(const int* dev_trs_stack, int offset, int stack_size, v
           clSetKernelArg(config->kernel, 1, sizeof(int), &offset), "set offset argument of transpose kernel", result);
         ACC_OPENCL_CHECK(clSetKernelArg(config->kernel, 2, sizeof(cl_mem), ACC_OPENCL_MEM(dev_data)),
           "set matrix-data argument of transpose kernel", result);
-        ACC_OPENCL_CHECK(
-          clEnqueueNDRangeKernel(queue, config->kernel, 1 /*work_dim*/, NULL, &work_size, &config->wgsize, 0, NULL, perf_event),
+        ACC_OPENCL_CHECK(clEnqueueNDRangeKernel(queue, config->kernel, 1 /*work_dim*/, NULL /*offset*/, &work_size, &config->wgsize,
+                           0, NULL, perf_event),
           "launch transpose kernel", result);
         /* eventually update performance counters inside of locked region */
 #    if !defined(OPENCL_LIBSMM_VALIDATE_TRANS)
@@ -1635,7 +1635,7 @@ int libsmm_acc_process(const int* host_param_stack, const int* dev_param_stack,
           ACC_OPENCL_CHECK(
             clSetKernelArg(config->kernel[kernel_idx], 5, sizeof(int), &bs), "set minibatch argument of SMM-kernel", result);
         }
-        ACC_OPENCL_CHECK(clEnqueueNDRangeKernel(queue, config->kernel[kernel_idx], 1 /*work_dim*/, NULL, &work_size,
+        ACC_OPENCL_CHECK(clEnqueueNDRangeKernel(queue, config->kernel[kernel_idx], 1 /*work_dim*/, NULL /*offset*/, &work_size,
                            config->wgsize + kernel_idx, 0, NULL, perf_event),
           "launch SMM-kernel", result);
         /* eventually update performance counters inside of locked region */