Hi Keld: Thanks for your email... 1. Can you pls point me to this benchmark (which shows 500MB/s)? I would like to know which CPU, HDDs and kernel version used to achieve this... 2. Secondly, I would like to understand how raid stack (md driver) scales as we add more cores...if single core gives ~500MB/s, can two core give ~1000MB/s? can four cores give ~2000MB/s? etc.... Thanks for your time. On Fri, Apr 2, 2010 at 4:05 AM, Keld Simonsen <keld@xxxxxxxxxx> 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
