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ESP32-S3 maximum theoretical PSRAM speed

Posted: Wed Feb 23, 2022 3:09 am
by accessays
Hello,

I am working on a project that requires the use of PSRAM and seems to be bottlenecked by its speed. I was wondering what the theoretical maximum PSRAM speed is? I currently use an N8R2 module, QSPI @120MHz mode. I've found out that NxR8 modules have Octal SPI, as well as are DTR instead of STR. But are those modules able to run @120MHz? In idf.py menuconfig if I select Octal SPI for PSRAM, the maximum selectable frequency becomes 80 MHz, which these modules would be (only) ~2.6 times faster than N8R2.

As I understand it, CPU frequency needs to evenly divide PSRAM frequency. Does that mean there could be a module using OPI PSRAM @160MHz, or possibly @240MHz?

Thanks in advance.