On Tue, Feb 24, 2009 at 3:52 PM, Alverson, Tom (Xetron)
<[email protected]> wrote:
> The P800 ... is "the highest performing controller
> in the SAS portfolio"

  Does it have dedicated silicon for XOR?  That's what matters.  This
might be called an "XOR engine" or "XOR co-processor" or "RAID-5
accelerator" or something along those lines.  In this past, it was
always a separate ASIC, although these days, I wouldn't be surprised
to find that microprocessors with a built-in XOR vector engine are
available.

> ... "supports over 100 hard drives" ...

  How many drives it can support has little-to-nothing to do with RAID
performance.  That's more about the actual SAS/SATA interface
controller chip.  The RAID part is almost always implemented as one or
more chips separate from the actual disk interface.

  (As a good design practice, a controller that can support more
drives should have more computational ability to go with it, but if
they're quoting 100+ drives they're obviously talking theory, not
real-world performance, so I wouldn't bet on that.)

-- Ben

~ Finally, powerful endpoint security that ISN'T a resource hog! ~
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