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Re: Music stutters during startup of programs

On Wed, Mar 01, 2006 at 09:31:59AM -0500, Lennart Sorensen wrote:

> md/raid5 uses a LOT of cpu.

The CPU load is not significant, that's not the problem. Also, the
kernel tells that something is disabling interrupts for too long (I
don't have the exact log at hand), and raid5 does not do such things.

> That would certainly explain why it takes a
> lot of cpu to access those drives.  I would call that perfectly expected
> bahaviour.  If you want low cpu use, stick to raid1 or use a hardware
> raid controller (like the 3ware or areca).

Actually HW raid is usually slower than SW raid. The real benefit of HW
raid is the reduced I/O bandwidth usage, which makes quite a difference
if you only have a single PCI bus. PCI-Express has more bandwidth (at
least in theory) so it should be less of a problem nowadays (you need
more disks to saturate the bus).


     MTA SZTAKI Computer and Automation Research Institute
                Hungarian Academy of Sciences

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