diff --git a/README.md b/README.md
index 45eb6667..3b36950a 100644
--- a/README.md
+++ b/README.md
@@ -118,7 +118,7 @@ CherryUSB Host Stack resource usage (GCC 10.2 with -O2):
 |usbh_hid.c     |  ~1400          | 256           | 4  + sizeof(struct usbh_hid) * x              | 0            |
 |usbh_video.c   |  ~3800          | 128           | 4  + sizeof(struct usbh_video) * x            | 0            |
 |usbh_audio.c   |  ~4100          | 128           | 4  + sizeof(struct usbh_audio) * x            | 0            |
-|usbh_rndis.c   |  ~4200          | 4096 + 2 * 2048(default)| sizeof(struct usbh_rndis) * 1       | 0            |
+|usbh_rndis.c   |  ~4200          | 512 + 2 * 2048(default)| sizeof(struct usbh_rndis) * 1       | 0            |
 |usbh_cdc_ecm.c |  ~2200          | 2 * 1514 + 16           | sizeof(struct usbh_cdc_ecm) * 1     | 0            |
 |usbh_cdc_ncm.c |  ~3300          | 2 * 2048(default) + 16 + 32   | sizeof(struct usbh_cdc_ncm) * 1  | 0         |
 |usbh_bluetooth.c |  ~1000        | 2 * 2048(default)   | sizeof(struct usbh_bluetooth) * 1       | 0            |
diff --git a/README_zh.md b/README_zh.md
index e59e4a68..ae3ff8b7 100644
--- a/README_zh.md
+++ b/README_zh.md
@@ -118,7 +118,7 @@ CherryUSB Host 协议栈资源占用说明（GCC 10.2 with -O2）：
 |usbh_hid.c     |  ~1400          | 256           | 4  + sizeof(struct usbh_hid) * x              | 0            |
 |usbh_video.c   |  ~3800          | 128           | 4  + sizeof(struct usbh_video) * x            | 0            |
 |usbh_audio.c   |  ~4100          | 128           | 4  + sizeof(struct usbh_audio) * x            | 0            |
-|usbh_rndis.c   |  ~4200          | 4096 + 2 * 2048(default)| sizeof(struct usbh_rndis) * 1       | 0            |
+|usbh_rndis.c   |  ~4200          | 512 + 2 * 2048(default)| sizeof(struct usbh_rndis) * 1       | 0            |
 |usbh_cdc_ecm.c |  ~2200          | 2 * 1514 + 16           | sizeof(struct usbh_cdc_ecm) * 1     | 0            |
 |usbh_cdc_ncm.c |  ~3300          | 2 * 2048(default) + 16 + 32   | sizeof(struct usbh_cdc_ncm) * 1  | 0         |
 |usbh_bluetooth.c |  ~1000        | 2 * 2048(default)   | sizeof(struct usbh_bluetooth) * 1       | 0            |
diff --git a/class/wireless/usbh_rndis.c b/class/wireless/usbh_rndis.c
index de84a126..fa53f840 100644
--- a/class/wireless/usbh_rndis.c
+++ b/class/wireless/usbh_rndis.c
@@ -13,7 +13,7 @@
 
 #define DEV_FORMAT "/dev/rndis"
 
-USB_NOCACHE_RAM_SECTION USB_MEM_ALIGNX uint8_t g_rndis_buf[4096];
+USB_NOCACHE_RAM_SECTION USB_MEM_ALIGNX uint8_t g_rndis_buf[512];
 
 #define CONFIG_USBHOST_RNDIS_ETH_MAX_FRAME_SIZE 1514
 #define CONFIG_USBHOST_RNDIS_ETH_MSG_SIZE       (CONFIG_USBHOST_RNDIS_ETH_MAX_FRAME_SIZE + 44)
@@ -80,7 +80,7 @@ static int usbh_rndis_init_msg_transfer(struct usbh_rndis *rndis_class)
     setup->bRequest = CDC_REQUEST_GET_ENCAPSULATED_RESPONSE;
     setup->wValue = 0;
     setup->wIndex = 0;
-    setup->wLength = 4096;
+    setup->wLength = sizeof(g_rndis_buf);
 
     ret = usbh_control_transfer(rndis_class->hport, setup, (uint8_t *)resp);
     if (ret < 0) {
@@ -138,7 +138,7 @@ int usbh_rndis_query_msg_transfer(struct usbh_rndis *rndis_class, uint32_t oid,
     setup->bRequest = CDC_REQUEST_GET_ENCAPSULATED_RESPONSE;
     setup->wValue = 0;
     setup->wIndex = 0;
-    setup->wLength = 4096;
+    setup->wLength = sizeof(g_rndis_buf);
 
     ret = usbh_control_transfer(rndis_class->hport, setup, (uint8_t *)resp);
     if (ret < 0) {
@@ -195,7 +195,7 @@ static int usbh_rndis_set_msg_transfer(struct usbh_rndis *rndis_class, uint32_t
     setup->bRequest = CDC_REQUEST_GET_ENCAPSULATED_RESPONSE;
     setup->wValue = 0;
     setup->wIndex = 0;
-    setup->wLength = 4096;
+    setup->wLength = sizeof(g_rndis_buf);
 
     ret = usbh_control_transfer(rndis_class->hport, setup, (uint8_t *)resp);
     if (ret < 0) {
@@ -262,7 +262,7 @@ int usbh_rndis_keepalive(struct usbh_rndis *rndis_class)
     setup->bRequest = CDC_REQUEST_GET_ENCAPSULATED_RESPONSE;
     setup->wValue = 0;
     setup->wIndex = 0;
-    setup->wLength = 4096;
+    setup->wLength = sizeof(g_rndis_buf);
 
     ret = usbh_control_transfer(rndis_class->hport, setup, (uint8_t *)resp);
     if (ret < 0) {