32 k iram, i = instruction, it's just static ram, all functions not prefixed with ICACHE_FLASH_ATTR will end here, it's loaded from spi flash on startup
80 k dram, d = data, also just static ram, for user data, it seems about 50 kb is free for user use
All other code is continuously fetched from spi flash, so it's a bit slower (about 4 times, I read).