diff --git a/app/src/board/board.h b/app/src/board/board.h
index de42ee3..93bea1b 100644
--- a/app/src/board/board.h
+++ b/app/src/board/board.h
@@ -58,7 +58,7 @@
 
 #define HEART_WAVE_SAMPLE_SERVICE_CACHE_SIZE (3 * 3 * 256)
 #define FILE_MAX_COUNT                       1
-#define SDCARD_MAX_FILE_SIZE                 (4 * 1024 * 1024)
+#define SDCARD_MAX_FILE_SIZE                 (3 * 1024 * 1024 * 1024)
 //
 #define SAMPLE_RATE      800
 #define SAMPLE_PRECISION 24
@@ -67,5 +67,5 @@
 #define APP_EVENT_QUEUE_SIZE 20
 
 #define APP_AUTO_SLEEP_TIMEOUT_MS (10 * 1000)
-#define APP_BYTE_EACH_FRAME 9
-#define APP_SENSOR_NUM 3
\ No newline at end of file
+#define APP_BYTE_EACH_FRAME       9
+#define APP_SENSOR_NUM            3
\ No newline at end of file