Date: Wed, 23 Aug 2006 11:34:18 -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: <ef10de9a0608230934j2d5d3304t508998b45e002e9@mail.gmail.com> In-Reply-To: <ef10de9a0608230913o3068a5bcqdb321905cb8c989c@mail.gmail.com> References: <44EC0B9B.5020705@withagen.nl> <003f01c6c68d$64688e60$b3db87d4@multiplay.co.uk> <44EC27C7.8060906@withagen.nl> <20060823120146.GA21578@rancor.immure.com> <ef10de9a0608230913o3068a5bcqdb321905cb8c989c@mail.gmail.com>
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On 8/23/06, Nikolas Britton <nikolas.britton@gmail.com> wrote: > 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. > I take that back. For PCIe 8x imagine a divided highway with 8 lanes in each direction. The speed limit for each lane of traffic is 250MegaBytes/sec. So if you can move 8 semi-trucks filled with data in parallel your effective data rate is 2GigaBytes/sec. simple eh? :-) -- BSD Podcasts @: http://bsdtalk.blogspot.com/ http://freebsdforall.blogspot.com/
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