SD card HPC Cyclone v to slow


Hello! Guys, I have a problem - we are trying to record the data stream on the SD card of the processor part, and we can not get the write speed higher than 4,975 MiBps
configuration of the Linux driver root@socfpga:~# cat /sys/kernel/debug/mmc0/ios
clock: 50000000 Hz
vdd: 21 (3.3 ~ 3.4 V)
bus mode: 2 (push-pull)
chip select: 0 (don’t care)
power mode: 2 (on)
bus width: 2 (4 bits)
timing spec: 2 (sd high-speed)
signal voltage: 0 (3.30 V)
driver type: 0 (driver type B)

In this case, the Uboot loads the Zimage at a speed of 19 MiBps.
how to solve this problem?


Hi Max,

I am afraid I was not able to understand your post. You say you are trying to record the data stream? is this for debugging purposes?

Can you clarify a bit more what are you trying to achieve?

Also, your issues may be hardware dependant, do you know what class of SD card are you using?



Hi, Ptorru!
My FPGA poll 16 channels (rs485) sensor system (2000 16-bit ADC’s), accumulates data and transfers it to the processor part where they assemble into 1 MB arrays and are written to the SD card - Samsung 128G 10 class.
Thanks for the answer, we solved the problem, we turn on the second processor, this processor only wrote on the card, and the speed increased to 16-19 MB per second, this suits us. Linux scheduler distracts wrote process - that’s why such a low SD speed.


Hi, Max. Will you help me? I also want to write data from the ADC -12 bit to micro SD card
64G using FPGA. I have a de10-nano-SoC board. Please write your email (Mailing address) I have a questions.Can you download your driver for Linux? What configuration was used? Do you work with Altera? Can you show the project?