diff --git a/interface.c b/interface.c
index d441eda..2609671 100644
--- a/interface.c
+++ b/interface.c
@@ -1,6 +1,7 @@
 //
 // Created by ary on 29.07.2026.
 //
+#include <stdatomic.h>
 #include <stdio.h>
 #ifdef _WIN32
     #include <windows.h>
@@ -18,7 +19,8 @@
 #include <stdlib.h>
 #include "helper.h"
 #include <pthread.h>
-#define WORKTHREADSIZE 32
+#include <stdatomic.h>
+#define WORKTHREADSIZE 16
 
 void* renderPixel(RenderArgs *arg, int pixelId) {
     RenderArgs *args = (RenderArgs*)arg;
@@ -57,11 +59,7 @@ void *workerLoop(void *arg) {
     RenderArgs *args = (RenderArgs*)arg;
 
     while (1) {
-        pthread_mutex_lock(&args->mutexKey);
-        int pixelId = args->nextPixelId;
-        args->nextPixelId++;
-        pthread_mutex_unlock(&args->mutexKey);
-
+        int pixelId = atomic_fetch_add(&args->nextPixelId, 1);
         if (pixelId >= args->pixelCount) break;
 
         renderPixel(args, pixelId);
@@ -73,9 +71,7 @@ void* monitorProgress(void *arg) {
     MonitorArgs *args = (MonitorArgs*)arg;
 
     while (1){
-        pthread_mutex_lock(args->mutexKey);
-        int pixelId = *args->nextPixelId;
-        pthread_mutex_unlock(args->mutexKey);
+        int pixelId = *atomic_load(&args->nextPixelId);
         if (pixelId >= args->pixelCount) break;
         double progress = 100.0 * pixelId / args->pixelCount;
         printf("progress: %lf%%\n", progress);
diff --git a/test.png b/test.png
index ecfeca5..4c6e7b1 100644
Binary files a/test.png and b/test.png differ