RPi file write speed test

[bmarkus]

I tested the file write speed on RPi with piCore, see result below:



SD card is Class 4 rated which means 4 Mbyte/s max. speed. You can see effect of RAM caching.

[coreplayer2]

I'm curious how you benchmark'd the SD card?


Also there are much faster SD cards available now with the need to save 4K video,  we need to try one of these bad boys http://www.toshiba.co.jp/about/press/2013_07/pr1601.htm   

I have one of their slower 90MB/s SDcard siblings around here somewhere...   will have to look for it  then maybe I should get a Raspberry Pi and join the fun

[bmarkus]

Measured with my own program written in Python.

What is commonly available here different Class 10 cards and UHS-I cards with up to 40 Mbyte/s write speed. 90 Mbyte/s is a read speed most likely.

Ask an RPi from Santa, it is a nice toy

[Franxoois]

Very interesting. I thought the ram was faster.

I tried this

Code: [Select]

tc@FLink2:~$ dd if=/dev/urandom of=/opt/test bs=10M count=5
5+0 records in
5+0 records out
52428800 bytes (50.0MB) copied, 44.505094 seconds, 1.1MB/s
tc@FLink2:~$ dd if=/opt/test of=/opt/test2
102400+0 records in
102400+0 records out
52428800 bytes (50.0MB) copied, 1.592277 seconds, 31.4MB/s
tc@FLink2:~$ dd if=/opt/test of=/opt/test2 bs=10M
5+0 records in
5+0 records out
52428800 bytes (50.0MB) copied, 0.558725 seconds, 89.5MB/s
tc@FLink2:~$ dd if=/opt/test of=/opt/test2 bs=20M
2+1 records in
2+1 records out
52428800 bytes (50.0MB) copied, 0.601817 seconds, 83.1MB/s
tc@FLink2:~$ dd if=/opt/test of=/opt/test2 bs=20M
2+1 records in
2+1 records out
52428800 bytes (50.0MB) copied, 0.572355 seconds, 87.4MB/s
tc@FLink2:~$ sudo dd if=/opt/test of=/mnt/mmcblk0p2/test3 bs=4M
12+1 records in
12+1 records out
52428800 bytes (50.0MB) copied, 13.180353 seconds, 3.8MB/s

[bmarkus]

Thanks. My program is writing 1024 bytes buffers during test in Python. I will play a bit with increased buffer length. For sure with larger buffers and using strict C you can reduce overhead when writing to RAM.

[spence91]

Does anyone know how this compares with other SD card writes?