diff --git a/examples/wifi/iperf/sdkconfig.defaults.esp32c2 b/examples/wifi/iperf/sdkconfig.defaults.esp32c2
index af67e48cf1..421500597e 100644
--- a/examples/wifi/iperf/sdkconfig.defaults.esp32c2
+++ b/examples/wifi/iperf/sdkconfig.defaults.esp32c2
@@ -9,7 +9,7 @@ CONFIG_ESP_WIFI_TX_BA_WIN=16
 CONFIG_ESP_WIFI_AMPDU_RX_ENABLED=y
 CONFIG_ESP_WIFI_RX_BA_WIN=14
 
-CONFIG_LWIP_TCP_SND_BUF_DEFAULT=11520
+CONFIG_LWIP_TCP_SND_BUF_DEFAULT=7200
 CONFIG_LWIP_TCP_WND_DEFAULT=11520
 CONFIG_LWIP_TCP_RECVMBOX_SIZE=32
 CONFIG_LWIP_UDP_RECVMBOX_SIZE=32
diff --git a/examples/wifi/iperf/sdkconfig.defaults.esp32s2 b/examples/wifi/iperf/sdkconfig.defaults.esp32s2
index 3cdbfdf3a8..37288848a9 100644
--- a/examples/wifi/iperf/sdkconfig.defaults.esp32s2
+++ b/examples/wifi/iperf/sdkconfig.defaults.esp32s2
@@ -9,7 +9,7 @@ CONFIG_ESP_WIFI_TX_BA_WIN=16
 CONFIG_ESP_WIFI_AMPDU_RX_ENABLED=y
 CONFIG_ESP_WIFI_RX_BA_WIN=16
 
-CONFIG_LWIP_TCP_SND_BUF_DEFAULT=28000
+CONFIG_LWIP_TCP_SND_BUF_DEFAULT=17280
 CONFIG_LWIP_TCP_WND_DEFAULT=28000
 CONFIG_LWIP_TCP_RECVMBOX_SIZE=32
 CONFIG_LWIP_UDP_RECVMBOX_SIZE=32