Re: new bottleneck section in wiki

Justin Piszcz <jpiszcz@xxxxxxxxxxxxxxx> · Thu, 3 Jul 2008 10:00:32 -0400 (EDT)

On Thu, 3 Jul 2008, Jon Nelson wrote:

Not true, Jon.  The test above was limited by the amount of data that a
single drive head can push to the controller with 100% sequential reads
of 64KB.  You can't say anything about chipset bottlenecks, because you
haven't created a condition where the chipset could even be a
bottleneck.  I/O is constrained by the disk drives.

Now, if you attached industrial class SSDs that operate at media speeds
with access time in the NS range, then you could be in a position to
benchmark chipset performance.

Well, that's true. However, perhaps I mis-spoke. What I was intending
on doing is showing that the chipset was /not/ the limiting factor
here, not checking it's maximum speed, but rather given what I know
about the drives individually, and then what the rates are with all
drives cookin', then I can say, "Well, at least the chipset or bus
aren't getting in the way." Note that I also added "or bus" to my
statement. Would you say that this statement is more accurate or am I
getting the terminology wrong, again?

Also check my thread regarding the Veliciraptors, when I read 

concurrently off of two of them, I do not get that great of performance.

Whereas the ports on the motherboard are excellent!

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