On Tue, 19 Jul 2005 jamesb.au@iinet.net.au wrote:

> I should get myself a book on SCSI as well.
>
> Are SCSI disks really all they are cracked up to be?  Is SCSI vs.
> ATA just a religious war, or are there technical merits to SCSI?

It often comes down to a religious war, and those who don't look at details
typically fall back to ATA because of price.

There are technical merits to SCSI.  As for the one that most end users care
about -- raw speed of data transfer with non-hotswap disks -- they aren't a
whole lot different.  It's when you get into more complex configurations
such as large numbers of disks, hotswapping, and high user concurrency that
SCSI shows its strengths.

The *manufacturing quality* of SCSI, however, tends to be better than that
for ATA disks, and IMHO, that is what is really reflected in the price
difference.  This is an artifact of SCSI drives being aimed at higher-end
workstation or server type environments, whereas ATA is aimed at consumer
environments.  One particular manufacturer's warranty periods illustrates
this difference pretty well:

http://www.maxtor.com/portal/site/Maxtor/menuitem.a14629af82eff9461400585760b46068/?channelpath=/en_us/Support/Warranty%20Services/Warranty%20Periods#bare_drive_warranty

Their ATA drives have only a 1 year (3 years for high end OEM only)
warranty, whereas their SCSI drives all carry a 5 year warranty.

I don't have any qualifying disks from Seagate to comment on their 5-year
warranty program that does apply to some (but not all?) of their ATA drives
currently being sold.

===

Disclaimer:  My main personal server uses two ATA133 disks in a RAID-1
configuration.  It's "good enough for me", as I can swap the disks right at
home if I need to do so.  (I did swap a disk from the above manufacturer
this year, when it died after only 5 months of service.)

However, if I were to co-locate the server, I'd likely switch to SCSI for
the drives' better chances at longevity.

-- 
-- Todd Vierling <tv@duh.org> <tv@pobox.com> <todd@vierling.name>