[Pc_Support] Re: Maxtor 100GB Serial ATA (SATA) drive $99.99 - $65.00rebate

[Bryan J. Smith]

Whaxiac Patrick <pberry2 at cfl.rr.com> wrote:
> Used SCSI Drives still have warrantees, in many cases; SCSI
> drives usually have 7 years on the warrantees!

That's because most are "enterprise" capacities -- typically
18, 36, 73 and 146GB.  They are not as leading edge and are
manufacturered to much higher tolerances.  But note you _can_
get them with ATA/SATA interfaces in more rarer cases.

Although also rare are some "commodity" capacity SCSI drives.
 A few vendors offer them, although not many anymore.  I
remember Quantum did, with a pretty high failure rate.

> I buy off of eBay, and try to get 50 Gb drives.

I too have a few 50GB, 3.5" x HH drive LVD U160 SCSI drives.

> Have several 18 Gb SCSI drives.  
> The thing is, the SCSI drives are built to run for 7 years,
> 24 hours a day, for 265 days, non-stop!

As do the few ATA/SATA models based on them.

> If you check the boxes and warrantees of most IDE 
> drives, they are meant to only run 8 hour days
> (intermittant duty).

Yes -- typically 5 x 14 maximum -- because most ATA/SATA
drives are "commodity" capacity/technology.

Although newer "commodity" capacity/technology has gotten
significantly better.  That's why Seagate offers its new NL35
series, and Western Digital offers the Caviar RE -- both
rated for 24x7 operation.

> The SCSI drives do multiple reads/writes, so are better
> suited for Linux, I believe.   

Native Command Queuing (NCQ) gives ATA the same queuing
capability.  Of course, that means you still have to have not
only a NCQ capable target (drive), but also a NCQ capable
host.  In most cases, the PC/OS is the host, which is least
ideal -- at least compared to SCSI which has an intelligent
host processor in its host adapter.

Only 2 vendors out there offer intelligent hardware cards
that do NCQ with an intelligent host on-board.  The 3Ware
Escalade 9550SX series (64-bit ASIC + PowerPC 400 series) and
the Areca ARC (IOP33x X-Scale series).

> Correct me, if I am wrong. 

Not wrong, just overly simplifying.



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