Richard Scobie wrote:
Mark Knecht wrote:
Once all of that is in place then possibly more cores will help, but I
suspect even then it probably hard to use 4 billion CPU cycles/second
doing nothing but disk I/O. SATA controllers are all doing DMA so CPU
overhead is relatively *very* low.
There is the RAID5/6 parity calculations to be considered on writes
and this appears to be single threaded. There is an experimental
multicore kernel option I believe, but recent discussion indicates
there may be some problems with it.
That is being polite. With that option set just doing a 'check' on a
raid-5 will generate 100s of threads and max out all cores. I was trying
to run the experimental FC13 64 bit kernel, and all of a sudden the
machine came to a crawl and the cpu use went to 95%+ on all cores. Also
drove the CPU temp way up, so I have to regard this as unsuitable for
anything but light testing.
--
Bill Davidsen <davidsen@xxxxxxx>
"We can't solve today's problems by using the same thinking we
used in creating them." - Einstein
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