It's hardly the same money, the drives are twice as much.
It's all about the controller baby with any kind of dive. A bad SCSI
controller will give sucky performance too, believe me. We had a
Compaq Smart Array 5304, and it's performance was _very_ sub par.
If someone has a simple benchmark test database to run, I would be
happy to run it on our hardware here.
Alex Turner
On Apr 6, 2005 3:30 AM, William Yu <wyu@talisys.com> wrote:
> Alex Turner wrote:
> > I'm no drive expert, but it seems to me that our write performance is
> > excellent. I think what most are concerned about is OLTP where you
> > are doing heavy write _and_ heavy read performance at the same time.
> >
> > Our system is mostly read during the day, but we do a full system
> > update everynight that is all writes, and it's very fast compared to
> > the smaller SCSI system we moved off of. Nearly a 6x spead
> > improvement, as fast as 900 rows/sec with a 48 byte record, one row
> > per transaction.
>
> I've started with SATA in a multi-read/multi-write environment. While it
> ran pretty good with 1 thread writing, the addition of a 2nd thread
> (whether reading or writing) would cause exponential slowdowns.
>
> I suffered through this for a week and then switched to SCSI. Single
> threaded performance was pretty similar but with the advanced command
> queueing SCSI has, I was able to do multiple reads/writes simultaneously
> with only a small performance hit for each thread.
>
> Perhaps having a SATA caching raid controller might help this situation.
> I don't know. It's pretty hard justifying buying a $$$ 3ware controller
> just to test it when you could spend the same money on SCSI and have a
> guarantee it'll work good under multi-IO scenarios.
>
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