Re: Intel SRCS16 SATA raid?

> -----Original Message-----
> From: Alex Turner [mailto:armtuk@gmail.com]
> Sent: Friday, April 15, 2005 9:44 AM
> To: Marinos Yannikos
> Cc: Joshua D. Drake; Mohan, Ross; pgsql-performance@postgresql.org
> Subject: Re: [PERFORM] Intel SRCS16 SATA raid?
>
> No offense to that review, but it was really wasn't that good,
> and drew bad conclusions from the data.  I posted it originaly
> and immediately regretted it.

I didn't read the whole thing, but it didn't seem that bad to me.

> See http://www.tweakers.net/reviews/557/18
>
> Amazingly the controller with 1Gig cache manages a write throughput
> of 750MB/sec on a single drive.
>
> quote:
> "Floating high above the crowd, the ARC-1120 has a perfect view on
> the struggles of the other adapters. "
>
> It's because the adapter has 1Gig of RAM, nothing to do with the RAID
> architecture, it's clearly caching the entire dataset.  The drive
> can't physicaly run that fast.

And that's pretty much exactly what the article says.  Even before the
part you quoted.  Not sure what the problem is there.

> These guys really don't know what they are doing.

They weren't pretending that the drive array was serving up data at
that rate directly from the physical media.  They clearly indicated
that they were testing controller cache speed with the small test.

> Curiously:
> http://www.tweakers.net/reviews/557/25
>
> The 3ware does very well as a data drive for MySQL.
> [...]

If you take a close look, they pretty much outright say that the Areca
controller does very poorly on the random accesses typical of DB work.
They also specifically mention that the 3ware still dominates the
competition in this area.

Dave


__
David B. Held
Software Engineer/Array Services Group
200 14th Ave. East,  Sartell, MN 56377
320.534.3637 320.253.7800 800.752.8129