Joshua Baker-LePain wrote: > On Thu, 12 Oct 2006 at 4:22pm, Bowie Bailey wrote > > > I have two identical servers. The only difference is that the first > > one has Maxtor 250G drives and the second one has Seagate 320G > > drives. > > > > OS: CentOS-4.4 (fully patched) > > CPU: dual Opteron 280 > > Memory: 16GB > > Raid card: 3ware 9550Sx-8LP > > Raid volume: 4-disk Raid 5 with NCQ and Write Cache enabled > > > > On the first server I have decent performance. Nothing spectacular, > > but good enough. The second one has about 1/3 the write speed. I > > can't find any difference between the systems. Both of them have > > the same stripe size, both have ext3 filesystems, both have write > > caching and NCQ turned on. I have already increased the read ahead > > setting to 16384 on both servers. > > Turn off NCQ. Last I knew, this was still 3ware's recommendation. I can try that, but when I tested on the first server, I found that disabling NCQ increased the read performance by 10M/s and decreased the write performance by 10M/s. Maybe I'll get different results from the Seagate drives. -- Bowie