diff --git a/src/cnn/cnn.c b/src/cnn/cnn.c
index fc4894b..9dd2dcb 100644
--- a/src/cnn/cnn.c
+++ b/src/cnn/cnn.c
@@ -12,6 +12,7 @@
 #include "include/make.h"
 
 #include "../include/colors.h"
+#include "../include/utils.h"
 #include "include/cnn.h"
 
 // Augmente les dimensions de l'image d'entrée
@@ -188,7 +189,7 @@ void forward_propagation(Network* network) {
         */
         if (k_i->cnn) { // Convolution
             make_convolution(k_i->cnn, input, output, output_width);
-            copy_input_to_input_z(output, output_z, output_depth, output_width, output_width);
+            copy_3d_array(output, output_z, output_depth, output_width, output_width);
             apply_function_to_matrix(activation, output, output_depth, output_width);
         }
         else if (k_i->nn) { // Full connection
@@ -197,7 +198,7 @@ void forward_propagation(Network* network) {
             } else { // Matrice -> Vecteur
                 make_dense_linearized(k_i->nn, input, output[0][0], input_depth, input_width, output_width);
             }
-            copy_input_to_input_z(output, output_z, 1, 1, output_width);
+            copy_3d_array(output, output_z, 1, 1, output_width);
             apply_function_to_vector(activation, output, output_width);
         }
         else { // Pooling
@@ -214,7 +215,7 @@ void forward_propagation(Network* network) {
                     printf("identifiant: %d, position: %d\n", pooling, i);
                 }
             }
-            copy_input_to_input_z(output, output_z, output_depth, output_width, output_width);
+            copy_3d_array(output, output_z, output_depth, output_width, output_width);
         }
     }
 }
@@ -281,16 +282,6 @@ void drop_neurones(float*** input, int depth, int dim1, int dim2, int dropout) {
     }
 }
 
-void copy_input_to_input_z(float*** output, float*** output_z, int output_depth, int output_rows, int output_columns) {
-    for (int i=0; i<output_depth; i++) {
-        for (int j=0; j<output_rows; j++) {
-            for (int k=0; k<output_columns; k++) {
-                output_z[i][j][k] = output[i][j][k];
-            }
-        }
-    }
-}
-
 float compute_mean_squared_error(float* output, float* wanted_output, int len) {
     /*
     * $E = \frac{ \sum_{i=0}^n (output_i - desired output_i)^2 }{n}$ 
diff --git a/src/include/utils.h b/src/include/utils.h
index 5893308..3305c44 100644
--- a/src/include/utils.h
+++ b/src/include/utils.h
@@ -38,4 +38,11 @@ extern "C"
 */
 bool check_cuda_compatibility();
 
+#ifdef __CUDACC__
+extern "C"
+#endif
+/*
+* Copier des valeurs d'un tableau de dimension 3 de mémoire partagée
+*/
+void copy_3d_array(float*** source, float*** dest, int dimension1, int dimension2, int dimension3);
 #endif
\ No newline at end of file
diff --git a/src/utils.c b/src/utils.c
index 8681646..5cee8ee 100644
--- a/src/utils.c
+++ b/src/utils.c
@@ -11,6 +11,10 @@
 
 #include "include/utils.h"
 
+#define BLOCKSIZE_x 16
+#define BLOCKSIZE_y 8
+#define BLOCKSIZE_z 8
+
 
 int i_div_up(int a, int b) { // Partie entière supérieure de a/b
     return ((a % b) != 0) ? (a / b + 1) : (a / b);
@@ -55,3 +59,37 @@ bool check_cuda_compatibility() {
     return false;
     #endif
 }
+
+#ifdef __CUDACC__
+__global__ void copy_3d_array_kernel(float*** source, float*** dest, int dimension1, int dimension2, int dimension3) {
+    int idx = threadIdx.x + blockDim.x*blockIdx.x; // < dimension1
+    int idy = threadIdx.y + blockDim.y*blockIdx.y; // < dimension2
+    int idz = threadIdx.z + blockDim.z*blockIdx.z; // < dimension3
+
+    if (idx >= dimension1 || idy >= dimension2 || idz >= dimension3) {
+        return;
+    }
+
+    dest[idx][idy][idz] = source[idx][idy][idz];
+}
+
+void copy_3d_array(float*** source, float*** dest, int dimension1, int dimension2, int dimension3) {
+    dim3 gridSize(i_div_up(dimension1, BLOCKSIZE_x), i_div_up(dimension2, BLOCKSIZE_y), i_div_up(dimension3, BLOCKSIZE_z));
+    dim3 blockSize(BLOCKSIZE_x, BLOCKSIZE_y, BLOCKSIZE_z);
+
+    copy_3d_array_kernel<<<gridSize, blockSize>>>(source, dest, dimension1, dimension2, dimension3);
+
+    gpuErrchk( cudaPeekAtLastError() );
+    gpuErrchk( cudaDeviceSynchronize() );
+}
+#else
+void copy_3d_array(float*** source, float*** dest, int dimension1, int dimension2, int dimension3) {
+    for (int i=0; i < dimension1; i++) {
+        for (int j=0; j < dimension2; j++) {
+            for (int k=0; k < dimension3; k++) {
+                dest[i][j][k] = source[i][j][k];
+            }
+        }
+    }
+}
+#endif
\ No newline at end of file
diff --git a/src/utils.cu b/src/utils.cu
index 8681646..bc60c5f 100644
--- a/src/utils.cu
+++ b/src/utils.cu
@@ -11,6 +11,10 @@
 
 #include "include/utils.h"
 
+#define BLOCKSIZE_x 16
+#define BLOCKSIZE_y 8
+#define BLOCKSIZE_z 8
+
 
 int i_div_up(int a, int b) { // Partie entière supérieure de a/b
     return ((a % b) != 0) ? (a / b + 1) : (a / b);
@@ -55,3 +59,38 @@ bool check_cuda_compatibility() {
     return false;
     #endif
 }
+
+#ifdef __CUDACC__
+__global__ void copy_3d_array_kernel(float*** source, float*** dest, int dimension1, int dimension2, int dimension3) {
+    int idx = threadIdx.x + blockDim.x*blockIdx.x; // < dimension1
+    int idy = threadIdx.y + blockDim.y*blockIdx.y; // < dimension2
+    int idz = threadIdx.z + blockDim.z*blockIdx.z; // < dimension3
+
+    if (idx >= dimension1 || idy >= dimension2 || idz >= dimension3) {
+        return;
+    }
+
+    dest[idx][idy][idz] = source[idx][idy][idz];
+}
+
+extern "C"
+void copy_3d_array(float*** source, float*** dest, int dimension1, int dimension2, int dimension3) {
+    dim3 gridSize(i_div_up(dimension1, BLOCKSIZE_x), i_div_up(dimension2, BLOCKSIZE_y), i_div_up(dimension3, BLOCKSIZE_z));
+    dim3 blockSize(BLOCKSIZE_x, BLOCKSIZE_y, BLOCKSIZE_z);
+
+    copy_3d_array_kernel<<<gridSize, blockSize>>>(source, dest, dimension1, dimension2, dimension3);
+
+    gpuErrchk( cudaPeekAtLastError() );
+    gpuErrchk( cudaDeviceSynchronize() );
+}
+#else
+void copy_3d_array(float*** source, float*** dest, int dimension1, int dimension2, int dimension3) {
+    for (int i=0; i < dimension1; i++) {
+        for (int j=0; j < dimension2; j++) {
+            for (int k=0; k < dimension3; k++) {
+                dest[i][j][k] = source[i][j][k];
+            }
+        }
+    }
+}
+#endif
\ No newline at end of file