At 12:34 PM 8/19/2005, Jeffrey W. Baker wrote:
On Fri, 2005-08-19 at 10:54 -0400, Ron wrote:
> Maxtor Atlas 15K II's.

> Areca's 1GB buffer RAID cards

The former are SCSI disks and the latter is an SATA controller.  The
combination would have a transaction rate of approximately 0.

You are evidently thinking of the Areca ARC-11xx controllers (and you are certainly right for that HW combination ;-) ). Those are not the only product Areca makes that can be upgraded to a 1GB cache.

Until SAS infrastructure is good enough, U320 SCSI and FC HD's remain the top performing HD's realistically available. At the most fundamental, your DBMS is only as good as your HD IO subsystem, and your HD IO subsystem is only as good as your HDs. As others have said here, skimping on your HDs is _not_ a good design choice where DBMSs are concerned.

As an aside, the Atlas 15K II's are now available in SAS:

I haven't seen independent benches on them, so I explicitly referenced the U320 Atlas 15K II's known performance numbers instead. As I said, Maxtor is claiming even better for the SAS version of the Atlas 15K II.

None of the SAS <-> PCI-X or PCI-E RAID cards I know of are ready for mass market yet, although a few are in beta..

I can vouch for the Areca controllers, however.  You can certainly
achieve pgbench transaction rates in the hundreds per second even with
only 5 7200RPM disks and 128MB cache.

Don't forget to buy the battery.


Hope this is helpful,
Ron Peacetree

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