On 12/09/2007, Greg Smith <gsmith@xxxxxxxxxxxxx> wrote: > On Wed, 12 Sep 2007, Phoenix Kiula wrote: > > > Scenario 1, SATAII: > > - Server: Asus RS120-E4/PA4 Dedicated Server > > - CPU: Single -- Intel Quad Core Xeon Processor x3210 Processor 2.13Ghz > > - RAM: 4Gb DDR2 Memory 667Mhz > > - Hard disk: 4 x Seagate ES SATAII HardDrive 7200RPM 250Gb (Total 500Gb) > > - Raid 10: 3Ware Raid 9650SE: http://www.acnc.com/04_01_10.html > > The typical 9650SE will normally come with 256MB of cache (the 2-port > version has 128MB, the 24-port on 512MB; you're probably getting one of > the middle ones which all have 256). This is a fast controller (sometimes > people complain about its RAID 5 which isn't an issue for you), it has > good drivers for most popular operating systems, and as long as you make > sure you're buying it from day one with the optional Battery Backup Unit > (BBU) so you can safely run it in write-back cache mode the performance of > this setup should be excellent for database use. > > > - Server: IBM e326m 1U Rackmount server > > - CPU: Double -- Opteron 275 is 2 x 2.2GHz, with 2 x 1MB L2 Cache > > - RAM: 4Gb PC3200 ECC Registered > > - Hard disk: 2 x 300GB SCSI 10K RPM > > - Raid 1: LSI Logic > > As far as I can tell IBM model uses the LSI Logic LSI53C1030 Fusion-MPT > Ultra320 SCSI Controller, usually abbreviated as the LSI 1030: > http://www.lsi.com/files/docs/marketing_docs/storage_stand_prod/raid/lsi53c1030_pb.pdf > > This is a very basic SCSI controller, not one of the LSI MegaRAID > controllers that are often recommended by people here. This particular > model appears to have no write cache as all, which means you'll get poor > performance with INSERTs under PostgreSQL. A quick search suggests it has > a general history of performance issues, possibly related to that; two > example reports are for Linux and FreeBSD are: > > http://stateless.geek.nz/2005/02/24/lsi-1030-raid-status-on-linux/ (may > have to grab this one from the Google cache instead: > http://64.233.169.104/search?q=cache:eMkvpB66H9QJ:stateless.geek.nz/2005/02/24/lsi-1030-raid-status-on-linux/+lsi+1030+raid+controller&hl=en&ct=clnk&cd=5&gl=us > ) > http://lists.freebsd.org/pipermail/freebsd-scsi/2005-January/001646.html > > Based on the well known strengths of the 3Ware controller vs. what appears > to be a very weak LSI controller, I would expect the Asus system above to > have massively better performance for your intended application than this > particular IBM one--even though it's possible the real-world performance > of the CPU/memory might be a little better on the Opteron box. The fact > that it will have 2X as many disks will just increase its lead. And now > you know why everyone wanted such specific information! Thank you for the detailed explanation Greg. Very, very useful! Just to confirm -- why do you say "[Opteron] will have 2X as many disks"? In the dual-Opteron setup above I have 2 hard disks with RAID1, whereas in the single-Xeon quad-core setup I have 4 disks with RAID 10. ---------------------------(end of broadcast)--------------------------- TIP 6: explain analyze is your friend
