Hi @neggles, I was basing my assumptions on the esp32-s2 chip technical reference manual, but esp32-s3 may have a different dma architecture. "This is new, I think? DMA access to external RAM was not previously possible, as far as I can tell" In esp32-s2 thecnical reference manual this is possible ...

Through the photos they are certainly not using octalspi, unless they divided the high nibble and low nibble for each memory or are using low nibble for both memories(what I highly doubt). The chips have only 8 pins. Regarding sqi we cannot infer anything, but i really hope they used an sqi bus for...

It looks like they're not using spi octal bus. And it looks like both flash memory and external ram memory share the same sqi bus. They should have made a chip that supported independent sqi bus access to each memory (flash and external ram). Obviously we can't be sure about any of this until the f...