On Wed, 25 Jun 2008, David Lethe wrote:
-----Original Message----- From: linux-raid-owner@xxxxxxxxxxxxxxx [mailto:linux-raid-owner@xxxxxxxxxxxxxxx] On Behalf Of Keld Jørn Simonsen Sent: Wednesday, June 25, 2008 1:49 PM To: Justin Piszcz Cc: Conway S. Smith; linux-raid@xxxxxxxxxxxxxxx Subject: Re: (was: Re: md: raid5 vs raid10 (f2,n2,o2) benchmarks [w/10 raptors]) These chunk sizes are profoundly meaningless if you plan on using them to estimate performance in the real world. The relationship between IO rate, IO throughput, and CPU overhead will be dramatically different with default md settings. Also consider that your kernel was recompiled with little or no cpu-specific optimization, so you are wasting cpu cycles .. and don't get me started on multicore vs. single core for such benchmarks. - David
1. In RAID5, these chunk sizes offered the best performance with bonnie++. 2. The CPU type in the config is optimized for the CPU in the host. 3. The host also runs IRQ balance. Justin.
