[Pc_Support] Re: Fujitsu or Seagate SCSI?

[Bryan J. Smith <b.j.smith at ieee.org>]

From: Jason Boxman <jasonb at edseek.com>
> I'd accept, "Jason, that's a stupid question, go away."
> Better than silence.

I wasn't sure if Fujistu fab'd their own disks.
I think so, but I'm not familiar with their process.

As far as Seagate, it depends.
Seagate has "commodity" SCSI disks up to 7,200rpm that
roll off the same line as their ATA/SATA.
So be careful on price.

You can typically tell these disks by their capacity, 80,
120, 160, 200, 250, 300, 320, 400, 500GB.

The more "enterprise" SCSI disks are typically 10,000rpm
or faster, and capacities of 9, 18, 36, 73, 146GB.

The "main difference" between the former and latter is the
quality of the balance in the platters.  The vibration of the
former is 3-8x worse than the latter, adding in other
factors such as materials and quality and it's not good for
24x7 operation.  Thus, the longevity and the MTBF of the
former is only 30% of the latter (1.4M to 0.4M), with the
latter rated _only_ for 50,000 restarts at 8hours/start.

There are some new "near-line" products from Seagate that
are commodity disks tested to higher tolerances, but they
are still rated to be "network managed 24x7" -- meaning the
platters do not actually operate 24x7, just the system they
are in.

BTW, Seagate's new commodity disks _are_ rated to 60C,
so that's nice (hence the return to 5 year warranties).  But
they still have the vibration aspects that wear out faster.


--
Bryan J. Smith   mailto:b.j.smith at ieee.org