On Mon, Jul 19, 2010 at 09:53:51AM +0600, Roman Mamedov wrote: > On Sun, 18 Jul 2010 17:32:25 -0700 > Konstantin Svist <fry.kun@xxxxxxxxx> wrote: > > > I looked around and found that chunk size > > of 512 should work better. > > Not true, at least with RAID5/6 a chunk size of 64K performs faster, see > http://louwrentius.blogspot.com/2010/05/raid-level-and-chunk-size-benchmarks.html > http://alephnull.com/benchmarks/sata2009/chunksize.html Thanks for these benchmarks, I added them to our benchmarks page on the wiki. It seems odd to me to use sata controllers on a 32-bit PCI bus, this should limit performance to about 130 MB/s - which is also seen tin the graphs. I think people would be better off using the on-board SATA controller, this would give normally something like 4 SATA ports connected to the southbridge, which normally is much faster than a 32-bit PCI bus, and also faster than many PCI-E busses. So I think using all the on-board SATA ports first, and the using the SATA ports on a bus-connceted controller would give better performance. In the louwrentius page, I miss info on which layout of RAID10 that is used. The 3 layouts (near, far, offset) has very different characteristics. best regards keld -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
