This is an standalone example of the bench code from SdFat using an SDIO PIO implementation from ZuluSCSI
This fork added some changes to improve large write performance.
Current numbers with a supposedly good SD Card and clock speed 250MHz:
Type is exFAT
Card size: 128.178 GB (GB = 1E9 bytes)
Manufacturer ID: 0X1B
OEM ID: SM
Product: ED2S5
Revision: 3.0
Serial number: 0XB210678A
Manufacturing date: 10/2022
FILE_SIZE_MB = 50
BUF_SIZE = 32768 bytes
Starting write test, please wait.
write speed and latency
speed,max,min,avg
KB/Sec,usec,usec,usec
26058.1,24395,1216,1254
26027.0,16960,1216,1256
Starting read test, please wait.
read speed and latency
speed,max,min,avg
KB/Sec,usec,usec,usec
24702.6,1395,1313,1326
24702.6,1392,1313,1326
Done
<BUILD_DIR> $ PICO_SDK_PATH=<PATH_TO_SDK> cmake <PATH_TO_SOURCE>
Target code will output bench results via UART and save results in bench.dat file on SD card root.