Messages in this thread | | | Date | Tue, 06 Aug 2002 09:47:57 -0700 | From | Ben Greear <> | Subject | Re: tigon3: 2466 and bad performance at 32bits/33mhz ? |
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Willy Tarreau wrote: > On Tue, Aug 06, 2002 at 12:35:08AM -0500, Robert Latham wrote: > >>The fast curve is with the 3c996B-T in the 64/66 slot. It peaks out >>around 850 Mbps. The slow curve is the same card in the 32/33 slot. >>It peaks around 180 Mbps. > > [snip] > >>So, am i looking at a hardware limitation? driver quirk? I'm open to >>any suggestions. > > > on a 32/33 slot, with a quad fast ethernet card, I can reach 400 Mbps > on good hardware. The *theorical* bandwidth limit is 1.06 Gbps for > 32 bits/33 Mhz. Of course, there's some overhead, but you would need 80% > overhead to get you numbers, not very likely... > > Perhaps this slot is on another bus, perhaps the latency timer is too > low and the card receives small chunks at once, or perhaps this bus > is shared with another hungry device ? > > Regards, > willy
I'm pushing 650Mbps on a 32/33 PCI bus using a Netgear GA620 GigE card (the card supports 64bit PCI). So, its not exactly a PCI bus limitation you are hitting unless your PCI chipset somehow really sucks.
Ben
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-- Ben Greear <greearb@candelatech.com> <Ben_Greear AT excite.com> President of Candela Technologies Inc http://www.candelatech.com ScryMUD: http://scry.wanfear.com http://scry.wanfear.com/~greear
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