I have an ESP32-S3 N16R8 device (i.e. 8MB SPI-RAM and 16MB Flash)

If I flash this build https://www.micropython.org/resources/firmware/GENERIC_S3_SPIRAM_OCT-20230623-unstable-v1.20.0-243-gd93316fe3.bin and then check free memory with gc.mem_free() I see 4254384

If I flash with this (older) build https://www.micropython.org/resources/firmware/GENERIC_S3_SPIRAM_OCT-20230621-unstable-v1.20.0-230-g41c91422f.bin and then check free memory with gc.mem_free() I see 8192976

I believe that the major difference between these builds is that the later one is built against ESP-IDF v 5.x