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ESP32S3, not able to understand SRAM limit

Posted: Tue May 20, 2025 10:05 am
by HareeshS
I have an ESP IDF project based on the ESP32-S3 Mini. According to the datasheet, the S3 should be having 512 KB of SRAM, but when I compile my project the memory usage summary says I have a total of 341760 bytes for DRAM and 16384 bytes of IRAM. I'm not able to understand where the rest of the RAM has gone or how it is being used. This confuses me in particular because if I compile the same project for an ESP32C3 mini, the DRAM partition is for the most part, a similar size (~320000 bytes).

I recently ran into an issue where WiFi initialization was failing (failed to init buffers) while NimBLE was enabled. I've had to temporarily downsize my application buffer(from 2*64KB arrays to 2*32KB arrays) for dev purposes to get the system to work, which seemed to indicate it was due to insufficient RAM, but rough calculations indicate that the theoretical 512KB (or heck, even 320KB) should be plenty sufficient.

Not sure how to proceed, any input would be great!