Adaptect raid performance with FreeBSD

[Ari Suutari]

On Wednesday 14 January 2004 15:02, Raymond Wiker wrote:
> Ari Suutari writes:
>  > dd if=/dev/rda1s1a of=/dev/null bs=1m count=100
>  > 100+0 records in
>  > 100+0 records out
>  > 104857600 bytes transferred in 4.193832 secs (25002814 bytes/sec)
>  >
>  > So, I get only about 25MB/s. Shouldn't I be getting something
>  > like 70 MB/s, or even more since there are two disks that
>  > can server read requests ?
>
>         Have you tried other block sizes? I think you may be able to
> get better results by going to a lower block size (e.g, 64k instead of
> 1m). Some experimentation will show which block size(s) work best.


	I tried with 32k, 64k, 256k and 512k. Speed is about the same
	with every block size. Block sizes less than 32k seem to give
	even worse performance.

		Ari S.	

-- 
Ari Suutari
Lemi, Finland