diff --git a/aad_coin_miner_cuda.c b/aad_coin_miner_cuda.c
index 672de15..4e7c374 100644
--- a/aad_coin_miner_cuda.c
+++ b/aad_coin_miner_cuda.c
@@ -67,7 +67,7 @@ static void mine_coins_cuda(u64_t max_attempts, double max_time)
 
   // Kernel configuration
   cd.block_dim_x = RECOMMENDED_CUDA_BLOCK_SIZE;
-  cd.grid_dim_x = 4096;  // Large grid for maximum GPU utilization
+  cd.grid_dim_x = 400;  // Large grid for maximum GPU utilization
 
   u32_t n_threads = cd.grid_dim_x * cd.block_dim_x;
 
@@ -89,7 +89,7 @@ static void mine_coins_cuda(u64_t max_attempts, double max_time)
   printf("Press Ctrl+C to stop\n\n");
 
   u64_t base_nonce = 0;
-  u32_t attempts_per_thread = 1024 * 8; // Increased attempts per thread
+  u32_t attempts_per_thread = 1024 * 16; // Increased attempts per thread
 
   double start_time = get_wall_time();
   time_measurement();
diff --git a/aad_sha1.h b/aad_sha1.h
index 5f7e1aa..9f75267 100644
--- a/aad_sha1.h
+++ b/aad_sha1.h
@@ -28,7 +28,7 @@
 //
 // we place this here to simplify things (aad_sha1_cuda_kernel.cu includes this file...)
 //
-#define RECOMMENDED_CUDA_BLOCK_SIZE  128
+#define RECOMMENDED_CUDA_BLOCK_SIZE  256
 
 
 //