2011-06-17 15:41, Edward Ned Harvey пишет:
From: Daniel Carosone [mailto:d...@geek.com.au]
Sent: Thursday, June 16, 2011 11:05 PM
the [sata] channel is idle, blocked on command completion, while
the heads seek.
I'm interested in proving this point. Because I believe it's false.
Just hand waving for the moment ... Presenting the alternative viewpoint
that I think is correct...
I'm also interested to hear the in-the-trenches specialists
and architechts on this point, however, the way it was
explained to me a while ago, disk caches and higher
interface speeds really matter in large arrays, where
you have one (okay, 8) links from your controller to a
backplane with dozens of disks, and the faster any of
these disks completes its bursty operation, the less
latency is induced on the array in whole.
So even if the spinning drive can not sustain 6Gbps,
its 64Mb of cache quite can spit out (or read in) its
bit of data, free the bus, and let the other many drives
spit theirs.
I am not sure if this is relevant to say a motherboard
controller where one chip processes 6-8 disks, but
maybe there's something to it too...
//Jim
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