Adaptect raid performance with FreeBSD

[lists at mediumgreen.com]

I think I heard Raymond Wiker say:
>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 ?


FWIW, on my mylex controller w/ raid 5 I'm getting:

# dd if=/dev/da0s1g of=/dev/null bs=1m count=100
100+0 records in
100+0 records out
104857600 bytes transferred in 3.707196 secs (28284882 bytes/sec)


and my dell perc3/dc (raid 5) is getting:

# dd if=/dev/amrd0s2e of=/dev/null bs=1m count=100
100+0 records in
100+0 records out
104857600 bytes transferred in 2.133522 secs (49147653 bytes/sec)


-matthew