Memory Usage Comparison

[中文]

This document is used to summarize the memory consumption when running common examples on different chips.

Comparison of Remaining Memory Size for Common Examples

Please note that the following test results have not undergone any memory optimization, they are simply the results obtained after directly running the basic examples in ESP-IDF. If you want to see the results after memory optimization, you can refer to next part, Example: Comparison of remaining memory size before and after memory optimization for ESP32-C3.

Comparison of Remaining Memory Size

example

ESP32

ESP32-C3

ESP32-C3(ECO7)

ESP32-C2

ESP32-S3

ESP32-C6

ESP32-H2

Empty project

305 K

330 K

330 K

196 K

389 K

465 K

264 K

Station

229 K

222 K

230 K

104 K

282 K

327 K

not support

Gatt_server

205 K

218 K

230 K

81 K

280 K

365 K

152 K

bleprph

209 K

219 K

233 K

100 K

281 K

379 K

170 K

provision(ble & Wi-Fi coexis)

164 K

134 K

152 K

22 K

193 K

262 K

not support

Note

This data was tested in IDF v5.3.1, using the default sdkconfig for each example.

Note

In ESP32-C3 (ECO7), there is more available RAM for wireless applications: 10 KB for Wi-Fi related, 15 KB for BLE, and 20 KB for Wi-Fi & BLE coexistence. If you want to use ESP32-C3 (ECO7), please enable the following settings in menuconfig:

  • Component config > Hardware Settings > Chip revision > Minimum Supported ESP32-C3 Revision > Rev 1.1

  • Component config > SPI Flash driver > Use esp_flash implementation in ROM

Example: Comparison of remaining memory size before and after memory optimization for ESP32-C3

Available free heap after optimization for ESP32-C3/ESP32-C2

example

Before memory optimization

After memory optimization

Physical memory

400 K

400 K

Station

230 K

304 K

Station + 1TLS(MQTTS)

210 K

300 K

bleprph_wifi_coex

178 K

248 K

Note

  • ESP32-C3 data tested in ESP-IDF v5.2.2

  • Print the station’s free heap memory after the got ip event

  • Station + 1TLS(MQTTS) data is based on the ESP-IDF mqtt/ssl example, print the free heap memory after the MQTT_EVENT_DATA event

  • In the ESP-IDF bleprph_wifi_coex example test, nimble BLE broadcast starts after the got ip event, then print the free heap memory