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
>
