diff --git a/halconf.h b/halconf.h
index 4042e8a..10bb5f0 100644
--- a/halconf.h
+++ b/halconf.h
@@ -320,7 +320,7 @@
 #ifdef TINYSA4
 #define SERIAL_USB_BUFFERS_SIZE     128
 #else
-#define SERIAL_USB_BUFFERS_SIZE     64
+#define SERIAL_USB_BUFFERS_SIZE     128
 #endif
 #endif
 
diff --git a/nanovna.h b/nanovna.h
index f74dcec..893d76d 100644
--- a/nanovna.h
+++ b/nanovna.h
@@ -723,13 +723,11 @@ extern volatile uint8_t redraw_request;
 // One pixel size
 typedef uint16_t pixel_t;
 
-//#define CELLWIDTH  (64/DISPLAY_CELL_BUFFER_COUNT)
-//#define CELLHEIGHT (32)
-#define CELLWIDTH  (16)
-#define CELLHEIGHT (16)
+#define CELLWIDTH  (64/DISPLAY_CELL_BUFFER_COUNT)
+#define CELLHEIGHT (32)
 
 // Define size of screen buffer in pixels (one pixel 16bit size)
-#define SPI_BUFFER_SIZE             (CELLWIDTH*CELLHEIGHT*DISPLAY_CELL_BUFFER_COUNT*2)
+#define SPI_BUFFER_SIZE             (CELLWIDTH*CELLHEIGHT*DISPLAY_CELL_BUFFER_COUNT)
 
 // SPI bus revert byte order
 // 16-bit gggBBBbb RRRrrGGG