Hi! Furthermore, I am not sure how much multiple CPU helps you. It seems like each array are handled by a separate process. This process possibly has internal data for management of the array, and it may be bound to run on a single processor, with no multithreading. Neil, could you explain if and how Linux MD takes advantage of multiple processors available, for a single array? Best regards keld On Fri, Apr 02, 2010 at 01:05:06PM +0200, Keld Simonsen wrote: > On Thu, Apr 01, 2010 at 08:07:25PM -0700, Learner Study wrote: > > Hi Keld: > > > > Do we have raid5/6 numbers for linux on any multi-core CPU? Most of > > the benchmarks I have seen on wiki show raid5 perf to be ~150MB/s with > > single core CPUs. How does that scale with multiple cores? Something > > like intel's jasper forest??? > > I have not checked if the benchmarks were on multi core machines. > It should not matter much if there were more than one CPU, but > of cause it helps a little. bonnie++ test reports cpu usage, and this > is not insignificant, say in the 20 -60 % range for some tests, > but nowhere near a bottleneck. There was one with a raid5 performance > seq read of about 500 MB/s with 36 % cpu utilization, so it is > definitely possible to come beyound 150 MB/s. The speed is largely > dependent on number of disk drives you employ. > > > > If available, can u pls point me to numbers with multi-core CPU? > > I dont have such benchmarks AFAIK. But new benchmarks are always welcome, > so please feel free to submit your findings. > > Best regards > keld > > > Thanks! > > > > On Wed, Mar 31, 2010 at 1:15 PM, Keld Simonsen <keld@xxxxxxxxxx> wrote: > > > On Wed, Mar 31, 2010 at 12:42:57PM -0700, Learner Study wrote: > > >> Hi Linux Raid Experts: > > >> > > >> I was looking at following wiki on raid perf on linux: > > >> > > >> https://raid.wiki.kernel.org/index.php/Performance > > >> > > >> and notice that the performance numbers are with 2.6.12 kernel. > > >> > > >> Do we perf numbers for: > > >> - latest kernel (something like 2.6.27 / 2.6.31) > > >> - raid 5 and 6 > > >> > > >> Can someone please point me to appropriate link? > > > > > > The link mentioned above has a number of other performance reports, for other levels of the kernel. > > > Anyway you should be able to get comparable results for newer kernels, the kernel has not become > > > slower since 2.6.12 on RAID. > > > > > > 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 > -- > 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 -- 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
