SATA vs SCSI ...

Ade Lovett ade at FreeBSD.org
Mon Jun 27 08:22:47 GMT 2005


Marc G. Fournier wrote:
> 
> looking at the specs between two cards, the SATA card(s) seem to rate
> ~100-150MB/s on each channel (if I'm reading right), with both the 3Ware
> and ICP cards having 4 individual channels ... looking at the SCSI
> cards, they are rated at 320MB/s, but that is total for the SCSI bus
> itself, right?

[snip]

As is often the case, these kind of comparisons are only working against
one side of the equation:

	"What happens when the system is operational"

Now, for your average desktop system, the converse:

	"What happens when things break"

becomes negligable.  Slap in new drive, slap in DVD/CD install media, Do
Stuff[tm], make working system.

In the Non-Stop (probably a trademark of Tandem) server-class world,
things work somewhat differently.  <flamebait>This is why we run
postgresql instead of mysql</flamebait>.  This is also the reason we run
U320 SCSI enclosures at twice the cost of equivalent SATA systems.  The
extra cash is well spent when things go wrong.

Absolute performance (assuming it can be measured correctly for the
specific environment you're in, as opposed to marketing figures) counts
for less than 50% of the whole equation when it comes to the purchase
decision.

-aDe


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