From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jeff Garzik Subject: Re: 3ware escalade vs software raid, from a different jeff Date: Thu, 19 Feb 2004 19:38:51 -0500 Sender: linux-raid-owner@vger.kernel.org Message-ID: <4035571B.505@pobox.com> References: <20040219175630.GA20790@datavibe.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20040219175630.GA20790@datavibe.net> To: "Rev. Jeffrey Paul" Cc: Joshua Baker-LePain , linux-raid@vger.kernel.org List-Id: linux-raid.ids Rev. Jeffrey Paul wrote: > I have always avoided the promise fasttrak cards for exactly that > reason ("hardware" being in quotes). It's my understanding that > they're not much more than their udma cards with drivers that do most > of the RAIDing. Actually, Promise is one of the very few companies that are doing something innovative in RAID... Their hardware is not 100% software RAID nor 100% hardware RAID. They instead follow the model of network cards -- perform all key operations on the board, and let the host CPU handle the rest. > It was also my understanding that the 3ware cards are true hardware > raid and are up to the task of something like this, which would also > explain why they're 4x the cost. Correct. > I am looking at a four disk raid5 or raid10, and it seems like > the interrupt load from four drives on four channels might be a bit > excesive. I'm going to be running critical services on the machine > that the drives are in (namely mysql and nfs) and don't want to worry > about performance. Once your spindles can max out your PCI bus bandwidth, -then- you can start worrying about PCI bandwidth and interrupt load ;-) Jeff