Re: how to test SD read/write speed
You can use DD to test disk speed, but it can easily lead to damaged data (partitions) if used incorrectly but is probably the most direct way of testing.
So for example my second internal disk is mount /media/HD2 so running this gives me the write speed:
that command writes 1GB to the disk, this large number is because the filesystem on the device will speed up the transfer by caching the data if a small transfer is carried out.
dd count=1k bs=1M if=/dev/zero of=/media/HD2/test.img
1024+0 records in
1024+0 records out
1073741824 bytes (1.1 GB) copied, 7.69365 s, 140 MB/s
This is a VERY dangerous command if you miss-type the output file so obviously take care using it and be sure to type correctly!
Desktop: E6420 (@3.4GHz, Water Cooled), 4GB DDR2, 1.6 TB HDs, X1950 Pro (OS Driver),
Dual Boot Win7/Jaunty, 19" 4:3 + 24" 16:9.
Laptop: Toshiba L30, T2080 Pentium Dual Core, 2 GB DDR2, 250GB Hard disk.