Date: Mon, 4 Dec 2000 11:26:43 -0600 (CST) From: Joe Greco <jgreco@ns.sol.net> To: hardware@freebsd.org Cc: jin@george.lbl.gov Subject: Re: high bandwidth I/O motherboard (any recommendation?) Message-ID: <200012041726.LAA38349@aurora.sol.net> In-Reply-To: <200012041717.LAA25440@earth.execpc.com> from "jgreco@execpc.com" at Dec 04, 2000 11:17:49 AM
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> Even the PCI spec. says 32-bit/33MHz PCI bus should have 132MBps > I/O bandwidth, but none of these 32-bit/33MHz PCI chipset (Intel > or VIA) can give that high I/O bandwidth. Yes, because that's a maximum theoretical number. Reality is always much worse unless you design a test that fits the hardware. Can't just expect the hardware to just "give" you that speed. > The best I/O bandwidth I have seen is about 60MBps under FreeBSD 4.2. I've seen 162MBps. > I am not sure if this is limited by the memory controller or the PCI > bus controller. (I don't think the O.S. can control this bandwidth.) > [...] > Any comments/suggestion on which motherboard can give 120MBps I/O bandwidth? ASUS CUR-DLS. It's relatively cheap (~$700ish). It sports two 64-bit 33 MHz PCI slots and four 32-bit 33 MHz PCI slots, and they are independent. This means that you can get more out of the system. Relatively cheap is all relative, of course, but compared to other hardware that you'd probably need to do 120MBps, it's pretty cheap. I have an array of 75 drives, not really optimized for throughput as much as massive amounts of storage, and when I did a dd on all drives simultaneously, I was seeing 162MBps with relatively low CPU loading. Four Adaptec 39160's made that possible. Obviously, one must split the load up among the PCI busses (or use the 64/33 exclusively) to get these speeds. Side note: the 64/66 version of this board is due out 1Q01, I believe. -- ... Joe ------------------------------------------------------------------------------- Joe Greco - Systems Administrator jgreco@ns.sol.net Solaria Public Access UNIX - Milwaukee, WI 414/342-4847 To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hardware" in the body of the message
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