FreeBSD 5.3b7and poor ata performance
Brad Knowles
brad at stop.mail-abuse.org
Mon Oct 25 14:40:09 PDT 2004
At 3:25 PM -0600 2004-10-25, Scott Long wrote:
> But as was said, there is always
> a performance vs. reliability tradeoff.
Well, more like "Pick two: performance, reliability, price" ;)
> And when you are talking about
> RAID-10 with a bunch of disks, you will indeed start seeing bottlenecks
> in the bus.
When you're talking about using a lot of disks, that's going to
be true for any disk subsystem that you're trying to get a lot of
performance out of.
The old rule was that if you had more than four disks per
channel, you were probably hitting saturation. I don't know if that
specific rule-of-thumb is still valid, but I'd be surprised if disk
controller performance hasn't roughly kept up with disk performance
over time.
--
Brad Knowles, <brad at stop.mail-abuse.org>
"Those who would give up essential Liberty, to purchase a little
temporary Safety, deserve neither Liberty nor Safety."
-- Benjamin Franklin (1706-1790), reply of the Pennsylvania
Assembly to the Governor, November 11, 1755
SAGE member since 1995. See <http://www.sage.org/> for more info.
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