Settings for best PSRAM Speed with ESP32 S3

[vroland]

Hello,

I'm working on an application where high-speed access to a framebuffer is critical, which resides in PSRAM. The framebuffer is processed and the result is stored in a queue, from which data is consumed by the LCD peripheral.
Afaik, the ESP32 S3 PSRAM should in the capable of reading at 80 MHz * 2 (ddr) * 1B (octal SPI) = 160 MB/s. However, in my tests I get ~84MB/s max when exceeding the cache size.
I noticed that the length of the DRAM cache line setting in the ESP-IDF 5.0 makes a significant difference, with longer cache line resulting in higher troughput. Are there any other settings I missed that could get me closer to that theoretical 160 MB/s?