ESP32-S3-SD_MMC-Speed-Test.ino

#include "math.h"
#include "FS.h"
#include "SD_MMC.h"

void testFileIO(fs::FS &fs, const char *path, uint32_t buffSize, uint32_t numMB)
{
  uint8_t *buff = (uint8_t *)ps_malloc(buffSize);

  File file = fs.open(path, FILE_WRITE);
  if (file)
  {
    size_t i;
    uint32_t start = millis();
    auto numToWrite = (numMB * 1024 * 1024) / buffSize;
    for (i = 0; i < numToWrite; i++)
    {
      file.write(buff, buffSize);
      yield();
    }
    uint32_t end = millis() - start;
    float kbps = numMB * 1024 * 1024 / end;

    USBSerial.printf("%u MB written using %d byte buffer for %u ms @ %.1f KBps\n", numMB, buffSize, end, kbps);
    file.close();
  }
  else
  {
    USBSerial.println("Failed to open file for writing");
  }

  file = fs.open(path);
  if (file)
  {
    uint32_t len = file.size();
    size_t flen = len;
    uint32_t start = millis();
    while (len)
    {
      size_t toRead = len;
      if (toRead > buffSize)
      {
        toRead = buffSize;
      }
      file.read(buff, toRead);
      len -= toRead;
    }
    uint32_t end = millis() - start;
    float kbps = numMB * 1024 * 1024 / end;
    USBSerial.printf("%u MB read using %d byte buffer for %u ms @ %.1f KBps\n", flen / 1024 / 1024, buffSize, end, kbps);
    file.close();
  }
  else
  {
    USBSerial.println("Failed to open file for reading");
  }

  delete[] buff;
}

void setup()
{
  USBSerial.begin(115200);
  SD_MMC.setPins(14, 13, 21, 41, 42, 12);
  if (!SD_MMC.begin("/sd", false, false, 20000))
  {
    USBSerial.println("Card Mount Failed");
    return;
  }

  for (int i = 0; i <= 7; i++)
  {
    testFileIO(SD_MMC, "/test.txt", 512 * pow(2, i), 8);
  }
}

void loop()
{
}