On Fri, 28 Jan 2005 10:59:58 -0500 Alex Turner <[EMAIL PROTECTED]> wrote:
> At this point I will interject a couple of benchmark numbers based on > a new system we just configured as food for thought. > > System A (old system): > Compaq Proliant Dual Pentium III 933 with Smart Array 5300, one RAID > 1, one 3 Disk RAID 5 on 10k RPM drives, 2GB PC133 RAM. Original > Price: $6500 > > System B (new system): > Self Built Dual Opteron 242 with 2x3ware 9500S-8MI SATA, one RAID 1 > (OS), one 4 drive RAID 10 (pg_xlog), one 6 drive RAID 10 (data) on 10k > RPM Raptors, 4GB PC3200 RAM. Current price $7200 > > System A for our large insert job: 125 minutes > System B for our large insert job: 10 minutes. > > There is no logical way there should be a 12x performance difference > between these two systems, maybe 2x or even 4x, but not 12x > > Bad controler cards/configuration will seriously ruin your day. 3ware > escalade cards are very well supported on linux, and work excellently. > Compaq smart array cards are not. Bonnie++ benchmarks show a 9MB/sec > write, 29MB/sec read on the RAID 5, but a 172MB/sec write on the > 6xRAID 10, and 66MB/sec write on the RAID 1 on the 3ware. > > With the right configuration you can get very serious throughput. The > new system is processing over 2500 insert transactions per second. We > don't need more RAM with this config. The disks are fast enough. > 2500 transaction/second is pretty damn fast. I agree that badly supported or configured cards can ruin your performance. However, don't you think moving pg_xlog onto a separate RAID and increasing your number of spindles from 3 to 6 on the data RAID would also have a significant impact on performance, no matter what card was used? I'm not sure you can give all the credit to the card on this one. --------------------------------- Frank Wiles <[EMAIL PROTECTED]> http://www.wiles.org --------------------------------- ---------------------------(end of broadcast)--------------------------- TIP 2: you can get off all lists at once with the unregister command (send "unregister YourEmailAddressHere" to [EMAIL PROTECTED])
