Re: SATA II and PCI-X vs PCI for Areca ARC-1110 RAID Adapter

[Allen Briggs <briggs%netbsd.org@localhost>]

On Wed, May 07, 2008 at 04:27:43PM -0400, George Georgalis wrote:
> On Wed 07 May 2008 at 11:41:55 AM -0700, Brian Buhrow wrote:
> >     Hello.  My suggestion is to check the performance, if possible, of a
> >hardware raid card versus raidframe in a given eenvironment.  The reason is
> >that I've run into a number of situations where raidframe out performs
> >hardware raid cards by a good margin, and this was somewhat of a surprise
> >until I started asking around, and found that, in fact, my experience
> >wasn't that unique.  In fact, I think if you google around for hardware
> >raid versus software raid, you'll find quite a few people hav had the
> >experience that I have.
> 
> this sounds rather contrary to what I'm familiar with... especially
> since this is a high end raid card. can you provide any references?
> a google does not confirm your assertion.

I would think that this would depend on the h/w raid cards, the
software, the raid level, the work load, the non-raid h/w, etc.
RAID 5 takes some CPU and memory.  I would expect that modern h/w
usually has plenty of overhead to handle RAID 5 while the dedicated
h/w is always trying to push the edge of what it can get away with
to minimize cost while keeping up on features.

IIRC, one of the on-line "labs" (Tom's Hardware?  Anandtech?) ran a
benchmark of several h/w RAID cards several years ago--looking at
performance of those cards with different RAID levels / drivers / 
work loads, etc., and there was a surprising range of performance.

If you really care about the performance, I wouldn't work much with
anecdotal reports.  I'd try to define as much as possible and try
to compare "apples to apples".

-allen

-- 
Allen Briggs  |  http://www.ninthwonder.com/~briggs/  |  
briggs%ninthwonder.com@localhost