Subject: Re: NetBSD Foundation's new machines
To: None <netbsd-advocacy@NetBSD.org>
From: Vincent <firstname.lastname@example.org>
Date: 07/23/2005 13:05:47
On Fri, Jul 22, 2005 at 03:07:33PM -0400, David Maxwell wrote:
> > On Fri, 22 Jul 2005 11:46:48 -0500
> > email@example.com wrote:
> > > > Anonymous CVS servers (two machines)
> > > > 2 CPU [2 cpu Opteron 244 (1.8GHz)]
> > > > 8 GB Memory (8 x 1GB PC3200 DDR 400MHz ECC memory)
> > > > 150 GB Disk (4 SATA 36.7GB 10K RPM drives)
> > > >
> > > > Build Servers (three machines)
> > > > 4 CPU [2 cpu (dual core) Opteron 265 (1.8GHz)]
> > > > 4 GB Memory (4 x 1GB PC3200 DDR 400MHz ECC memory)
> > > > 210 GB Disk (3 SATA 74GB 10K RPM 8MB Raptor drives)
> > >
> > > Just out of curiosity, why were such small hard drives purchased? Or
> > > were these older ones that were already laying around? I was just
> > > wondering, because the going price for 200 GB SATA drives is only about
> > > $100. Anything smaller is considerably more expensive per GB.
> > The disks are 10K RPM, not 7200 or 5400 RPM as the drives you are
> > suggesting. I suppose speed is a more important factor than disk size
> > in those machines.
> SCSI interfaces are a more important factor by far. They still handle
> multiple concurrent requests far better than IDE or SATA drives.
> SATA is starting to add support for queued requests, but from what I
> heard last, it's not well supported yet, and not supported at all in
> many models of drives.
Thanks for your replies. The general consensus seems to be that the
decision was primarily based on speed.
For our machines, we have always bought the lowest price/MB drives
because we have not seen anywhere near enough benefit to accommodate
3 times the price for 20-30% increase in drive speed. That can make
a significant difference when copying large files, but we have found the
speed difference to be insignificant for most normal random access
because of Unix file system caching. Especially on machines with large
amounts of RAM, the drive is accessed such a small percentage of the
time that the speed increase is hardly noticeable. I guess if you are
running MicroShaft it might make a big difference :-).