Re: [Discuss-gnuradio] File sink causes "S" errors

[Nick Foster]

On Wed, 2010-10-06 at 13:17 +0900, Thomas Hobiger wrote:
> Dear all,
> 
> Thanks for all the comments and suggestions.
> 
> 
> > Can you benchmark your hard disk for sustained rate? 
> 
> Here are the results from a simple DD test
> 
> > dd if=/dev/zero of=/SSD/test.bin bs=1K count=1000000
> 1000000+0 records in
> 1000000+0 records out
> 1024000000 bytes (1.0 GB) copied, 11.5431 s, 88.7 MB/s
> 
> > dd if=/dev/zero of=/SSD/test.bin bs=10K count=100000
> 100000+0 records in
> 100000+0 records out
> 1024000000 bytes (1.0 GB) copied, 9.8813 s, 104 MB/s
> 
> > dd if=/dev/zero of=/SSD/test.bin bs=100K count=10000
> 10000+0 records in
> 10000+0 records out
> 1024000000 bytes (1.0 GB) copied, 9.87555 s, 104 MB/s
> 
> > dd if=/dev/zero of=/SSD/test.bin bs=1000K count=1000
> 1000+0 records in
> 1000+0 records out
> 1024000000 bytes (1.0 GB) copied, 9.76347 s, 105 MB/s
> 

Try /dev/random instead of /dev/zero. SSDs are known to use data
compression algorithms to run-length-encode drive data on the fly, to
increase bandwidth and reduce data replication on the drive. It's
possible that your drive is performing write optimization on your test
which is not applicable to the real world.

--n