diff --git a/hw/VX_config.h b/hw/VX_config.h
index f809ab82..63be0e93 100644
--- a/hw/VX_config.h
+++ b/hw/VX_config.h
@@ -180,7 +180,7 @@
 #endif
 
 #ifndef SMEM_LOG_SIZE
-#define SMEM_LOG_SIZE   17
+#define SMEM_LOG_SIZE   19
 #endif
 
 #ifndef IO_BASE_ADDR
diff --git a/kernel/include/gemmini_mmio.h b/kernel/include/gemmini_mmio.h
index cefac42b..ebd3a5ba 100644
--- a/kernel/include/gemmini_mmio.h
+++ b/kernel/include/gemmini_mmio.h
@@ -5,8 +5,12 @@
 #endif
 
 #define SMEM_BASE 0xff000000
-//#define SMEM_SIZE 0x4000
-#define SMEM_SIZE 0x10000
+// 16KB
+// #define SMEM_SIZE 0x4000
+// 64KB
+// #define SMEM_SIZE 0x10000
+// 256KB
+#define SMEM_SIZE 0x40000
 
 #define SMEM_MASK (SMEM_SIZE - 1)
 #define SMEM_ADDR_END (SMEM_BASE + SMEM_SIZE)