diff --git a/driver/conv.cu b/driver/conv.cu
index 5d039a4f86..b5bf0a2473 100644
--- a/driver/conv.cu
+++ b/driver/conv.cu
@@ -614,7 +614,7 @@ int main()
                                                              nrepeat);
 #endif
 
-#if 1
+#if 0
     if(S == 3 && R == 3)
     {
         host_winograd_3x3_convolution(in_nchw, wei_kcsr, out_nkhw_host, lower_pads, upper_pads);
diff --git a/driver/device_implicit_gemm_convolution_2_cnhw_csrk_knhw.cuh b/driver/device_implicit_gemm_convolution_2_cnhw_csrk_knhw.cuh
index e801e15b2b..7f3ddc7299 100644
--- a/driver/device_implicit_gemm_convolution_2_cnhw_csrk_knhw.cuh
+++ b/driver/device_implicit_gemm_convolution_2_cnhw_csrk_knhw.cuh
@@ -128,7 +128,8 @@ void device_implicit_gemm_convolution_2_cnhw_csrk_knhw(InDesc,
 
     constexpr unsigned BlockSize = 64;
 #elif 1
-    // 1x1, 28x28, 128 threads
+    // 1x1, 28x28, 128 threads, no lds-double-buffer
+    // 1x1, 28x28, 128 threads, with lds-double-buffer, max_register = 128
     constexpr unsigned BPerBlock = 64;
     constexpr unsigned KPerBlock = 128;
     constexpr unsigned CPerBlock = 8;
@@ -215,37 +216,37 @@ void device_implicit_gemm_convolution_2_cnhw_csrk_knhw(InDesc,
         cudaEventCreate(&start);
         cudaEventRecord(start, 0);
 
-#if 1
+#if 0
         gridwise_implicit_gemm_convolution_2_cnhw_csrk_knhw
 #else
         gridwise_implicit_gemm_convolution_2_cnhw_csrk_knhw_lds_double_buffer
 #endif
-            <GridSize,
-             BlockSize,
-             T,
-             decltype(in_cnhw_desc),
-             decltype(wei_csrk_desc),
-             decltype(out_knhw_desc),
-             BPerBlock,
-             KPerBlock,
-             CPerBlock,
-             BPerThread,
-             KPerThread,
-             GemmThreadPerColumnPerCluster,
-             GemmThreadPerRowPerCluster,
-             GemmMPerThreadSubC,
-             GemmNPerThreadSubC,
-             GemmMLevel0Cluster,
-             GemmNLevel0Cluster,
-             GemmMLevel1Cluster,
-             GemmNLevel1Cluster,
-             GemmKPerThreadLoop,
-             InBlockCopyThreadPerDim0,
-             InBlockCopyThreadPerDim1,
-             WeiBlockCopyThreadPerDim0,
-             WeiBlockCopyThreadPerDim1,
-             InBlockCopyDataPerRead,
-             WeiBlockCopyDataPerRead>
+        <GridSize,
+         BlockSize,
+         T,
+         decltype(in_cnhw_desc),
+         decltype(wei_csrk_desc),
+         decltype(out_knhw_desc),
+         BPerBlock,
+         KPerBlock,
+         CPerBlock,
+         BPerThread,
+         KPerThread,
+         GemmThreadPerColumnPerCluster,
+         GemmThreadPerRowPerCluster,
+         GemmMPerThreadSubC,
+         GemmNPerThreadSubC,
+         GemmMLevel0Cluster,
+         GemmNLevel0Cluster,
+         GemmMLevel1Cluster,
+         GemmNLevel1Cluster,
+         GemmKPerThreadLoop,
+         InBlockCopyThreadPerDim0,
+         InBlockCopyThreadPerDim1,
+         WeiBlockCopyThreadPerDim0,
+         WeiBlockCopyThreadPerDim1,
+         InBlockCopyDataPerRead,
+         WeiBlockCopyDataPerRead>
             <<<grid_dim, block_dim>>>(in_cnhw_desc,
                                       static_cast<T*>(in_cnhw_device_buf.GetDeviceBuffer()),
                                       wei_csrk_desc,
diff --git a/src/include/blockwise_2d_tensor_op.cuh b/src/include/blockwise_2d_tensor_op.cuh
index 1231a3863b..ff4476d0b7 100644
--- a/src/include/blockwise_2d_tensor_op.cuh
+++ b/src/include/blockwise_2d_tensor_op.cuh
@@ -512,4 +512,196 @@ struct Blockwise2dTensorCopy3
             }
         }
     }
+
+#if 1
+    __device__ constexpr unsigned GetRegisterClipboardSize() const
+    {
+        static_assert(is_same<Float, float>::value, "wrong! only support float!\n");
+
+        constexpr auto I0 = Number<0>{};
+        constexpr auto I1 = Number<1>{};
+
+        constexpr unsigned L0 = CopyLengths{}.Get(I0);
+        constexpr unsigned L1 = CopyLengths{}.Get(I1);
+
+        constexpr unsigned thread_per_d1 = (L1 + DataPerRead - 1) / DataPerRead;
+        constexpr unsigned thread_per_d0 = BlockSize / thread_per_d1;
+
+        return DataPerRead * (L0 + thread_per_d0 - 1) / thread_per_d0;
+    }
+
+    __device__ void RunLoadRegisterClipboard(const Float* __restrict__ p_src,
+                                             Float* p_clipboard) const
+    {
+        static_assert(is_same<Float, float>::value, "wrong! only support float!\n");
+
+        using Float2 = float2;
+        using Float4 = float4;
+
+        constexpr auto I0 = Number<0>{};
+        constexpr auto I1 = Number<1>{};
+
+        constexpr unsigned L0 = CopyLengths{}.Get(I0);
+        constexpr unsigned L1 = CopyLengths{}.Get(I1);
+
+        constexpr unsigned thread_per_d1 = (L1 + DataPerRead - 1) / DataPerRead;
+        constexpr unsigned thread_per_d0 = BlockSize / thread_per_d1;
+
+        constexpr unsigned num_active_thread = thread_per_d0 * thread_per_d1;
+
+        if(BlockSize > num_active_thread)
+        {
+            if(get_thread_local_1d_id() >= num_active_thread)
+            {
+                return;
+            }
+        }
+
+        constexpr unsigned nloop_d0 = L0 / thread_per_d0;
+
+        constexpr unsigned src_loop_stride = SrcDesc{}.GetStride(I0) * thread_per_d0;
+        constexpr unsigned dst_loop_stride = DstDesc{}.GetStride(I0) * thread_per_d0;
+
+        for(unsigned iloop = 0; iloop < nloop_d0; ++iloop)
+        {
+            if(DataPerRead == 1)
+            {
+                p_clipboard[iloop] = p_src[mSrcMyThreadOffset + iloop * src_loop_stride];
+            }
+            else if(DataPerRead == 2)
+            {
+                *(reinterpret_cast<Float2*>(p_clipboard + iloop * 2)) =
+                    *(reinterpret_cast<const Float2*>(p_src + mSrcMyThreadOffset +
+                                                      iloop * src_loop_stride));
+            }
+            else if(DataPerRead == 4)
+            {
+                *(reinterpret_cast<Float4*>(p_clipboard + iloop * 4)) =
+                    *(reinterpret_cast<const Float4*>(p_src + mSrcMyThreadOffset +
+                                                      iloop * src_loop_stride));
+            }
+            else
+            {
+                assert(false);
+            }
+        }
+
+        constexpr bool has_tail_d0 = (L0 > nloop_d0 * thread_per_d0);
+
+        if(has_tail_d0)
+        {
+            constexpr unsigned tail_d0 = L0 - nloop_d0 * thread_per_d0;
+
+            if(get_thread_local_1d_id() < tail_d0 * thread_per_d1)
+            {
+                if(DataPerRead == 1)
+                {
+                    p_clipboard[nloop_d0] = p_src[mSrcMyThreadOffset + nloop_d0 * src_loop_stride];
+                }
+                else if(DataPerRead == 2)
+                {
+                    *(reinterpret_cast<Float2*>(p_clipboard + nloop_d0 * 2)) =
+                        *(reinterpret_cast<const Float2*>(p_src + mSrcMyThreadOffset +
+                                                          nloop_d0 * src_loop_stride));
+                }
+                else if(DataPerRead == 4)
+                {
+                    *(reinterpret_cast<Float4*>(p_clipboard + nloop_d0 * 4)) =
+                        *(reinterpret_cast<const Float4*>(p_src + mSrcMyThreadOffset +
+                                                          nloop_d0 * src_loop_stride));
+                }
+                else
+                {
+                    assert(false);
+                }
+            }
+        }
+    }
+
+    __device__ void RunStoreRegisterClipboard(const Float* __restrict__ p_clipboard,
+                                              Float* __restrict__ p_dst) const
+    {
+        static_assert(is_same<Float, float>::value, "wrong! only support float!\n");
+
+        using Float2 = float2;
+        using Float4 = float4;
+
+        constexpr auto I0 = Number<0>{};
+        constexpr auto I1 = Number<1>{};
+
+        constexpr unsigned L0 = CopyLengths{}.Get(I0);
+        constexpr unsigned L1 = CopyLengths{}.Get(I1);
+
+        constexpr unsigned thread_per_d1 = (L1 + DataPerRead - 1) / DataPerRead;
+        constexpr unsigned thread_per_d0 = BlockSize / thread_per_d1;
+
+        constexpr unsigned num_active_thread = thread_per_d0 * thread_per_d1;
+
+        if(BlockSize > num_active_thread)
+        {
+            if(get_thread_local_1d_id() >= num_active_thread)
+            {
+                return;
+            }
+        }
+
+        constexpr unsigned nloop_d0 = L0 / thread_per_d0;
+
+        constexpr unsigned src_loop_stride = SrcDesc{}.GetStride(I0) * thread_per_d0;
+        constexpr unsigned dst_loop_stride = DstDesc{}.GetStride(I0) * thread_per_d0;
+
+        for(unsigned iloop = 0; iloop < nloop_d0; ++iloop)
+        {
+            if(DataPerRead == 1)
+            {
+                p_dst[mDstMyThreadOffset + iloop * dst_loop_stride] = p_clipboard[iloop];
+            }
+            else if(DataPerRead == 2)
+            {
+                *(reinterpret_cast<Float2*>(p_dst + mDstMyThreadOffset + iloop * dst_loop_stride)) =
+                    *(reinterpret_cast<const Float2*>(p_clipboard + iloop * 2));
+            }
+            else if(DataPerRead == 4)
+            {
+                *(reinterpret_cast<Float4*>(p_dst + mDstMyThreadOffset + iloop * dst_loop_stride)) =
+                    *(reinterpret_cast<const Float4*>(p_clipboard + iloop * 4));
+            }
+            else
+            {
+                assert(false);
+            }
+        }
+
+        constexpr bool has_tail_d0 = (L0 > nloop_d0 * thread_per_d0);
+
+        if(has_tail_d0)
+        {
+            constexpr unsigned tail_d0 = L0 - nloop_d0 * thread_per_d0;
+
+            if(get_thread_local_1d_id() < tail_d0 * thread_per_d1)
+            {
+                if(DataPerRead == 1)
+                {
+                    p_dst[mDstMyThreadOffset + nloop_d0 * dst_loop_stride] = p_clipboard[nloop_d0];
+                }
+                else if(DataPerRead == 2)
+                {
+                    *(reinterpret_cast<Float2*>(p_dst + mDstMyThreadOffset +
+                                                nloop_d0 * dst_loop_stride)) =
+                        *(reinterpret_cast<const Float2*>(p_clipboard + nloop_d0 * 2));
+                }
+                else if(DataPerRead == 4)
+                {
+                    *(reinterpret_cast<Float4*>(p_dst + mDstMyThreadOffset +
+                                                nloop_d0 * dst_loop_stride)) =
+                        *(reinterpret_cast<const Float4*>(p_clipboard + nloop_d0 * 4));
+                }
+                else
+                {
+                    assert(false);
+                }
+            }
+        }
+    }
+#endif
 };
diff --git a/src/include/gridwise_implicit_gemm_convolution_2_cnhw_csrk_knhw_lds_double_buffer.cuh b/src/include/gridwise_implicit_gemm_convolution_2_cnhw_csrk_knhw_lds_double_buffer.cuh
index 7e10a62faf..16165f6195 100644
--- a/src/include/gridwise_implicit_gemm_convolution_2_cnhw_csrk_knhw_lds_double_buffer.cuh
+++ b/src/include/gridwise_implicit_gemm_convolution_2_cnhw_csrk_knhw_lds_double_buffer.cuh
@@ -262,8 +262,26 @@ __global__ void gridwise_implicit_gemm_convolution_2_cnhw_csrk_knhw_lds_double_b
         __syncthreads();
 
         // load next data
+#if 0
         blockwise_in_copy.Run(p_in_global_block_offset, p_in_block_next);
         blockwise_wei_copy.Run(p_wei_global_block_offset, p_wei_block_next);
+#elif 0
+        blockwise_in_copy.Run(p_in_global_block_offset, p_in_block_next);
+
+        Float p_wei_register_clipboard[blockwise_wei_copy.GetRegisterClipboardSize()];
+
+        blockwise_wei_copy.RunLoadRegisterClipboard(p_wei_global_block_offset,
+                                                    p_wei_register_clipboard);
+#elif 1
+        Float p_in_register_clipboard[blockwise_in_copy.GetRegisterClipboardSize()];
+        Float p_wei_register_clipboard[blockwise_wei_copy.GetRegisterClipboardSize()];
+
+        blockwise_in_copy.RunLoadRegisterClipboard(p_in_global_block_offset,
+                                                   p_in_register_clipboard);
+
+        blockwise_wei_copy.RunLoadRegisterClipboard(p_wei_global_block_offset,
+                                                    p_wei_register_clipboard);
+#endif
 
         // compute on current data
         //   a series of GEMM
@@ -283,6 +301,13 @@ __global__ void gridwise_implicit_gemm_convolution_2_cnhw_csrk_knhw_lds_double_b
                      f_accum);
             }
         }
+
+#if 0
+        blockwise_wei_copy.RunStoreRegisterClipboard(p_wei_register_clipboard, p_wei_block_next);
+#elif 1
+        blockwise_in_copy.RunStoreRegisterClipboard(p_in_register_clipboard, p_in_block_next);
+        blockwise_wei_copy.RunStoreRegisterClipboard(p_wei_register_clipboard, p_wei_block_next);
+#endif
     }
 
     // last computation