im using an Esp32 s3 with 16MB Flash and 8MB PSRAM. These are my pins.Using psram as buffer for data , it takes 134010 us to read 1 MB. (I dont use the default pin numbers to have a easier path from the esp32 to sdcard slot since im wiring it manually with very thin copper wires. Have 10k pullups on cmd and data0 to data3) ->
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int clk = 10;
int d2 = 5;
int d3 = 4;
int cmd = 3;
int d0 = 2;
int d1 = 1;
It works both in 1 bit and 4 bit modes. However i expected 1 bit mode reads to be slower and it is arround 2 MB/s but i expected abit more from 4 bit mode as i can only get 7.5MB/s. Which is weird since with a clock of 40MHz youd expect max 20MB/s but even in the worst case of overhead atleast 15MB/s. Is this the maximum esp32 s3 can do for reads or is there something i need to enable /avoid. Also does the 10k pullups cause it since some interfaces may reduce clock speed if too much errors occur or instablity.
im using arduino core but i also used espidf with vscode to test aswell but im only getting 250KB/s in 4 bit mode there. the PSRAM option is not available in that sdmmc example espidf provides. And it seems even though before i saw that sdmmc supporting uhs 50 before it doesnt anymore atleast in espidf 5.4