Date: Wed, 23 Aug 2006 11:13:37 -0500 From: "Nikolas Britton" <nikolas.britton@gmail.com> To: "Bob Willcox" <bob@immure.com> Cc: amd64@freebsd.org, stable@freebsd.org, Steven Hartland <killing@multiplay.co.uk> Subject: Re: suggestions for SATA RAID cards Message-ID: <ef10de9a0608230913o3068a5bcqdb321905cb8c989c@mail.gmail.com> In-Reply-To: <20060823120146.GA21578@rancor.immure.com> References: <44EC0B9B.5020705@withagen.nl> <003f01c6c68d$64688e60$b3db87d4@multiplay.co.uk> <44EC27C7.8060906@withagen.nl> <20060823120146.GA21578@rancor.immure.com>
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On 8/23/06, Bob Willcox <bob@immure.com> wrote: > On Wed, Aug 23, 2006 at 12:02:47PM +0200, Willem Jan Withagen wrote: > > Steven Hartland wrote: > > >The Areca cards I can recommend. Highpoint 1820a is surprisingly good > > >for its price and the later cards have better performance still apparently. > > >N.B. Use the min stripe size when creating the array for max performance > > >with this card under FreeBSD. > > > > I was more thinking along the lines of a HighPoint 2720, but perhaps a 1820 > > would also do fine. What device driver would one use with that. > > > > [Ahhh, 'man -k highpoint' is your friend] > > Now what I liked about the 3ware stuff was that there are tools to work the > > raid from within FreeBSD. So that would require the newers ones... > > > > But the hardware list is only showing the 2320 and 2322 with a rr232x(4) > > driver. Which sort of makes me wonder for all the other stuff and their > > drivers. > > > > The motherboard has both PCI-X and PCI-E so that should not be a connector > > problem. Now which bus is faster: 64Bit PCI-X at 133 Mhz, or a PCI-E 16x? > > The x16 PCI-E has considerably faster theoretical speed than 133 PCI-X > (appx. 4GBs vs. 1GBs). However, the RAID controllers that I've seen are > at most x8 so they are only capable of transfer rates half that fast > (2GBs). Personally, I would go with PCI-E since in some performance > tests I did with Areca cards last year (both PCI-E and PCI-X) there > appeared to be a slight performance advantage to the PCI-E cards (sorry, > I don't recall any of the specifics anymore, so please take that for > what it's worth). > I agree. PCIe 8x is a faster bus and it's typically connected directly to the MCH (north bridge) unlike PCI-X which is stuck on the ICH (south bridge). Also the 2GB/s that was quoted for PCIe 8x is it's one-way data rate "after" calculating in overhead. It's a dual simplex interface meaning it has one path to send data and another path to receive data. Imagine a simple two lane road.
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