diff --git a/fftma_module/gen/include/chunk_array.h b/fftma_module/gen/include/chunk_array.h
index 8781492..6f11aad 100644
--- a/fftma_module/gen/include/chunk_array.h
+++ b/fftma_module/gen/include/chunk_array.h
@@ -21,6 +21,7 @@ typedef struct chunk_array {
     double* mmap_array;
     buffer_t* buffer1;
     buffer_t* buffer2;
+    buffer_t** buffers;
 }chunk_array_t;
 
 chunk_array_t* chunk_array_create(char* filename, size_t total_size);
@@ -31,8 +32,6 @@ bool chunk_array_get(chunk_array_t* chunk_array, size_t pos, double *value_ptr);
 
 bool chunk_array_save(chunk_array_t* chunk_array, size_t pos, double valor);
 
-void chunk_array_flush(chunk_array_t* chunk_array);
-
 size_t chunk_array_size(chunk_array_t* chunk_array);
 
 #endif
\ No newline at end of file
diff --git a/fftma_module/gen/lib_src/chunk_array.c b/fftma_module/gen/lib_src/chunk_array.c
index 75eb201..6f583cf 100644
--- a/fftma_module/gen/lib_src/chunk_array.c
+++ b/fftma_module/gen/lib_src/chunk_array.c
@@ -3,7 +3,8 @@
 #include "stdlib.h"
 #include <sys/mman.h>
 
-#define MAX_CHUNK_SIZE 2048*2048
+#define MAX_CHUNK_SIZE 2048
+#define N_BUFFERS 3
 
 int min(int value1, int value2) {
     if (value1 < value2) return value1;
@@ -28,23 +29,17 @@ bool inside_buffer(chunk_array_t* chunk_array,int init_pos, size_t pos) {
 }
 
 void chunk_array_free(chunk_array_t* chunk_array) {
-  	//fclose(chunk_array->fp);
-    munmap(chunk_array->mmap_array, chunk_array->total_size * sizeof(double));
-    buffer_free(chunk_array->buffer1);
-    buffer_free(chunk_array->buffer2);
+    if (chunk_array->mmap_array) munmap(chunk_array->mmap_array, chunk_array->total_size * sizeof(double));
+    for (int i = 0; i < N_BUFFERS; i++) {
+        buffer_free(chunk_array->buffers[i]);
+    }
+    free(chunk_array->buffers);
 	free(chunk_array);  
 }
 
-void chunk_array_flush(chunk_array_t* chunk_array) {
-    buffer_flush(chunk_array, chunk_array->buffer1);
-    buffer_flush(chunk_array, chunk_array->buffer2);
-}
-
 void buffer_flush(chunk_array_t* chunk_array, buffer_t* buffer) {
     if (buffer->dirty) {
         int mod = get_mod(chunk_array, buffer->init_pos);
-        //fseek(chunk_array->fp, buffer->init_pos * sizeof(double), SEEK_SET);
-        //fwrite(buffer->data, sizeof(double), mod, chunk_array->fp);
         memcpy(&chunk_array->mmap_array[buffer->init_pos], buffer->data, mod * sizeof(double));
         
         buffer->dirty = false;
@@ -59,8 +54,6 @@ void buffer_update(chunk_array_t* chunk_array, buffer_t* buffer, size_t pos) {
     buffer->init_pos = new_init * chunk_array->chunk_size;
     int mod = get_mod(chunk_array, buffer->init_pos);
 
-    //fseek(chunk_array->fp, buffer->init_pos * sizeof(double), SEEK_SET);
-    //fread(buffer->data, sizeof(double), chunk_array->chunk_size, chunk_array->fp);
     memcpy(buffer->data, &chunk_array->mmap_array[buffer->init_pos], mod * sizeof(double));
 }
 
@@ -94,65 +87,75 @@ chunk_array_t* chunk_array_create(char* filename, size_t total_size) {
         return NULL;
     }
 
-    chunk_array->mmap_array = mmap ( NULL, total_size*sizeof(double), PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, 0, 0 );
-
-    if (chunk_array->mmap_array == NULL) {
-        return NULL;
-    }
-
     chunk_array->chunk_size = min(MAX_CHUNK_SIZE, total_size);
 
-    chunk_array->buffer1 = buffer_create(chunk_array->chunk_size);
+    if (chunk_array->chunk_size*N_BUFFERS < total_size) {
 
-    if (chunk_array->buffer1 == NULL) {
-        fclose(chunk_array->fp);
-        free(chunk_array);
-        return NULL;
+        chunk_array->mmap_array = mmap ( NULL, total_size*sizeof(double), PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, 0, 0 );
+
+        if (chunk_array->mmap_array == NULL) {
+            return NULL;
+        }
+        
     }
 
-    chunk_array->buffer2 = buffer_create(chunk_array->chunk_size);
+    chunk_array->buffers = malloc(sizeof(buffer_t) * N_BUFFERS);
 
-    if (chunk_array->buffer2 == NULL) {
-        //fclose(chunk_array->fp);
-        buffer_free(chunk_array->buffer1);
-        free(chunk_array);
-        return NULL;
-    }
+    chunk_array->buffers[0] = buffer_create(chunk_array->chunk_size);
+
+    chunk_array->buffers[0]->init_pos = 0;
 
-    memcpy(chunk_array->buffer1->data, chunk_array->mmap_array, chunk_array->chunk_size * sizeof(double));
-    chunk_array->buffer1->init_pos = 0;
-    if (total_size > chunk_array->chunk_size) {
-        int mod = get_mod(chunk_array, chunk_array->buffer1->init_pos + chunk_array->chunk_size);
-        memcpy(chunk_array->buffer2->data, &chunk_array->mmap_array[chunk_array->chunk_size], mod * sizeof(double));
-        chunk_array->buffer2->init_pos = chunk_array->chunk_size;
+    for (int i = 1; i<N_BUFFERS; i++) {
+        if (total_size > i*chunk_array->chunk_size) {
+            chunk_array->buffers[i] = buffer_create(chunk_array->chunk_size);
+            chunk_array->buffers[i]->init_pos = chunk_array->chunk_size;
+        } else {
+            break;
+        }
     }
+
     chunk_array->filename = filename;
     chunk_array->total_size = total_size;
     return chunk_array;
 }
 
 buffer_t* chunk_array_update(chunk_array_t* chunk_array, size_t pos) {
-    int distance_to_1 = abs(chunk_array->buffer1->init_pos - pos);
-    int distance_to_2 = abs(chunk_array->buffer2->init_pos - pos);
 
-    if (distance_to_1 < distance_to_2) {
-        buffer_update(chunk_array, chunk_array->buffer1, pos);
-        return chunk_array->buffer1;
+    buffer_t* buffer = chunk_array->buffers[0];
+    int distance = abs(buffer->init_pos - pos);
+
+    printf("[CHUNK UPDATE][%s] pos: %d \n",chunk_array->filename, pos);
+
+    for(int i=1; i<N_BUFFERS; i++) {
+        int new_distance = abs(chunk_array->buffers[i]->init_pos - pos);
+        if (new_distance < distance) {
+            distance = new_distance;
+            buffer = chunk_array->buffers[i];
+        }
     }
-    buffer_update(chunk_array, chunk_array->buffer2, pos);
-    return chunk_array->buffer2;
+
+    buffer_update(chunk_array, buffer, pos);
+    return buffer;
+
+
 }
 
 bool chunk_array_get(chunk_array_t* chunk_array, size_t pos, double *valor) {
-    buffer_t* buffer;
-    if (inside_buffer(chunk_array, chunk_array->buffer1->init_pos, pos)) {
-        buffer = chunk_array->buffer1;
+    // full memory
+    if (chunk_array->total_size <= chunk_array->chunk_size) {
+        *valor=chunk_array->buffers[0]->data[pos];
+        return true;
     }
-    else if (inside_buffer(chunk_array, chunk_array->buffer2->init_pos, pos)) {
-        buffer = chunk_array->buffer2;
+
+    // mmap
+    buffer_t* buffer = NULL;
+    for (int i = 0; i<N_BUFFERS; i++) {
+        if (inside_buffer(chunk_array, chunk_array->buffers[i]->init_pos, pos)) {
+            buffer = chunk_array->buffers[i];
+        }
     }
-    else {
-        // need to update one buffer
+
+    if (!buffer) {
         buffer = chunk_array_update(chunk_array, pos);
     }
 
@@ -163,15 +166,23 @@ bool chunk_array_get(chunk_array_t* chunk_array, size_t pos, double *valor) {
 
 
 bool chunk_array_save(chunk_array_t* chunk_array, size_t pos, double valor) {
-	buffer_t* buffer;
-    if (inside_buffer(chunk_array, chunk_array->buffer1->init_pos, pos)) {
-        buffer = chunk_array->buffer1;
+    // full memory
+    if (chunk_array->total_size <= chunk_array->chunk_size) {
+        chunk_array->buffers[0]->data[pos]=valor;
+        chunk_array->buffers[0]->dirty = true;
+        return true;
     }
-    else if (inside_buffer(chunk_array, chunk_array->buffer2->init_pos, pos)) {
-        buffer = chunk_array->buffer2;
+
+    // mmap
+	buffer_t* buffer = NULL;
+
+    for (int i = 0; i<N_BUFFERS; i++) {
+        if (inside_buffer(chunk_array, chunk_array->buffers[i]->init_pos, pos)) {
+            buffer = chunk_array->buffers[i];
+        }
     }
-    else {
-        // need to update one buffer
+
+    if (!buffer) {
         buffer = chunk_array_update(chunk_array, pos);
     }
     int real_pos = pos%get_mod(chunk_array, buffer->init_pos);
diff --git a/fftma_module/gen/lib_src/fftma2.c b/fftma_module/gen/lib_src/fftma2.c
index 8b28a2e..5cfcb6f 100644
--- a/fftma_module/gen/lib_src/fftma2.c
+++ b/fftma_module/gen/lib_src/fftma2.c
@@ -69,42 +69,25 @@ void FFTMA2(struct vario_mod variogram, struct grid_mod grid, int n[3], struct r
 
     printf("termine covariance\n");
 
-    chunk_array_flush(covar);
-
     /*power spectrum*/
     fourt(covar, ireal, n, NDIM, 1, 0, workr, worki);
 
-    chunk_array_flush(covar);
-    chunk_array_flush(ireal);
-
     /*organization of the input Gaussian white noise*/
     solver = 0;
     prebuild_gwn(grid, n, realin, realization, solver, seed);
 
-    chunk_array_flush(realization);
-
     /*forward fourier transform of the GWN*/
     fourt(realization, ireal, n, NDIM, 1, 0, workr, worki);
 
-    chunk_array_flush(realization);
-    chunk_array_flush(ireal);
-
     /* build realization in spectral domain   */
     build_real(n, NTOT, covar, realization, ireal);
 
-    chunk_array_flush(realization);
-
     chunk_array_free(covar);
-    remove("covar.txt");
 
     /*backward fourier transform*/
     fourt(realization, ireal, n, NDIM, 0, 1, workr, worki);
 
-    chunk_array_flush(realization);
-    chunk_array_flush(ireal);
-
     chunk_array_free(ireal);
-    remove("ireal.txt");
 
     free(workr);
     free(worki);
diff --git a/fftma_module/gen/lib_src/fourt.c b/fftma_module/gen/lib_src/fourt.c
index 59cde2a..c504b79 100644
--- a/fftma_module/gen/lib_src/fourt.c
+++ b/fftma_module/gen/lib_src/fourt.c
@@ -3,7 +3,7 @@
 #include <time.h>
 #include "chunk_array.h"
 
-/*fast fourier transform                                                   */
+/*     fast fourier transform                                              */
 /*     THE COOLEY-TUKEY FAST FOURIER TRANSFORM                             */
 /*     EVALUATES COMPLEX FOURIER SERIES FOR COMPLEX OR REAL FUNCTIONS.     */
 /*     THAT IS, IT COMPUTES                                                */
@@ -333,8 +333,13 @@ void fourt(chunk_array_t* datar, chunk_array_t* datai, int nn[3], int ndim, int
                 chunk_array_save(datar, i, valuerj - tempr);
                 chunk_array_save(datai, i, valueij - tempi);
 
-                chunk_array_get(datar, j, &valuerj);
-                chunk_array_get(datai, j, &valueij);
+                //chunk_array_get(datar, j, &valuerj);
+                //chunk_array_get(datai, j, &valueij);
+                printf("start\n");
+                printf("[GET] %d\n", j);
+                printf("[SAVE] %d\n", i);
+                printf("[SAVE] %d\n", j);
+                printf("end\n");
 
                 chunk_array_save(datar, j, valuerj + tempr);
                 chunk_array_save(datai, j, valueij + tempi);