NRF5340 USB MSC SD card access data is onle 355KB/s

[jgzou]

Hello Nordic support,

I am using the zephyr\samples\subsys\usb\mass example with an SD card. SPIM4 work on 16MHz.When I check this example on a Windows 11 machine, I observe data transfer rate of 355 Kbps,whether it's reading or writing. Is it possible to get a higher data transfer rate?

Regards,

[Simonr]

Hi

It is possible, yes, but not very easy. ~355 kbps is approximately what you can expect from the standard USB MSC example. To increase this throughput it will require that you read from the SD card and write to USB at the same time, requiring a rather complicated buffering solution. The maximum transmission will be ~1Mbps (3 times what you're currently doing).

Best regards,

Simon

[Simonr]

To determine the exact max transmission you can achieve we need the following information:

SoC: nRF5340

SPI frequency supported by SD card: 16MHz?

SD card model:

RAM disk:

Best regards,

Simon