diff --git a/xfibres_gpu.cc b/xfibres_gpu.cc
index 717e1838de675b7d79c02d7fe38d77c12df680c2..7a4e852ddef08aa5a79506ae5e4e5b074d49abaf 100644
--- a/xfibres_gpu.cc
+++ b/xfibres_gpu.cc
@@ -15,7 +15,7 @@
 #include <sys/time.h>
 #include "CUDA/init_gpu.h"
 
-#define SIZE_SUB_PART 9000 
+#define SIZE_SUB_PART 12800 //16 SM * 800 
 
 using namespace Xfibres;