Chris Mauritz wrote:
> > Ive done some superficial performance tests using dd, 55MB/s write
> > 12MB/s read, interestingly i did get 42MB/s write using just a 2 way ide
> > raid0, and got 55MB/s write with one drive per channel on four channels
> > (i had no problem writing, just reading) so surprisingly i dont think
> > the drive interface is my bottleneck.
>
> I find those numbers rather hard to believe. I've not yet heard of a
> disk (IDE or SCSI) that can reliably dump 22mb/sec which is what your
> 2 drive setup implies. Something isn't right.
Check http://www.tomshardware.com , they review the Promise IDE RAID
card
(the hacked one for $30). They get some pretty insane throughputs
on some ATA66 drives.
> RAID0 seemed to scale rather linearly. I don't think there would be
> much of a problem getting over 100mbits/sec on an array of 8-10 ultra2
I tested a 3 drive RAID0 set where 1 disk = 1.7 M/sec, 2 disks = 3.4
M/sec,
but 3 disks only = 3.9 M/sec. These were 5 M/sec disks on a AHA2940.
I think SCSI bus overhead and contention issues play an important role.
Ed
--
Edward Schernau http://www.schernau.com
Network Architect mailto:[EMAIL PROTECTED]
Rational Computing Providence, RI, USA
