I haven't had very good experiences with the Adaptec cards either.
If you can take the performance hit, the Mylex ExtremeRAID cards
come in a 3-channel variety. You could then split your array
into 3 chunks of 3-4 disks each and use hardware RAID instead of
the software raidtools.
Cheers,
Chris
> From [EMAIL PROTECTED] Mon Jul 10 17:10:27 2000
>
> i have not used adaptec 160 cards, but i have found most everything else they
> make to be very finicky about cabling and termination, and have had hard
> drives give trouble on adaptec that worked fine on other cards.
>
> my money stays with a lsi/symbios/ncr based card. tekram is a good vendor, and
> symbios themselves have a nice 64 bit wide, dual channel pci scsi card.
>
> which does lead to the point about pci. even _IF_ you could get the entire pci
> bus to do your disk transfers, you will find that you would still need more
> bandwidth for stuff like using your nics.
>
> so, i suggest you investigate a motherboard with either 66mhz pci or 64 bit
> pci, or both. perhaps alpha?
>
> allan
>
> Gregory Leblanc <[EMAIL PROTECTED]> said:
>
> > > -----Original Message-----
> > > From: Seth Vidal [mailto:[EMAIL PROTECTED]]
> > > Sent: Monday, July 10, 2000 12:23 PM
> > > To: [EMAIL PROTECTED]
> > > Cc: [EMAIL PROTECTED]
> > > Subject: speed and scaling
> > >
> > > So were considering the following:
> > >
> > > Dual Processor P3 something.
> > > ~1gb ram.
> > > multiple 75gb ultra 160 drives - probably ibm's 10krpm drives
> > > Adaptec's best 160 controller that is supported by linux.
> > >
> > > The data does not have to be redundant or stable - since it can be
> > > restored from tape at almost any time.
> > >
> > > so I'd like to put this in a software raid 0 array for the speed.
> > >
> > > So my questions are these:
> > > Is 90MB/s a reasonable speed to be able to achieve in a raid0 array
> > > across say 5-8 drives?
> >
> > Assuming sequential reads, you should be able to get this from good drives.
> >
> > > What controllers/drives should I be looking at?
> >
> > I'm not familiar with current top-end drives, but you should be looking for
> > at least 4MB of cache on the drives. I think the best drives that you'll
> > find will be able to deliver 20MB/sec without trouble, possibly a bit more.
> > I seem to remember somebody on this liking Adaptec cards, but nobody on the
> > SPARC lists will touch the things. I might look at a Tekram, or a Symbios
> > based card, I've heard good things about them, and they're used on some of
> > the bigger machines that I've worked with. Later,
> > Grego
> >
>
>
>
>
--
Christopher Mauritz
[EMAIL PROTECTED]
