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!
--
* Greg Smith gsmith@xxxxxxxxxxxxx http://www.gregsmith.com Baltimore, MD
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