Messages in this thread | | | Date | Tue, 6 Aug 2002 00:35:08 -0500 | From | Robert Latham <> | Subject | tigon3: 2466 and bad performance at 32bits/33mhz ? |
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I've got a 3com 3C996B-T (copper) and a tyan 2466 motherboard. The kernel is 2.4.19-rc1-ac2, and i'm using the tg3 v0.99 (Jun 11, 2002).
When i run the 3C996B-T in the 64-bit/66-MHz slot, i get great performance. When i run the card in the 32-bit/66-MHz slot, i get pretty bad performance. Here's a netpipe graph to demonstrate:
http://www-unix.mcs.anl.gov/~robl/storage_box/tg3-32_33.2.png
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.
Is a maximum throughput of ~180 MBits/sec all that can be hoped for? I don't have the hardware to verify, but http://www.cs.uni.edu/~gray/gig-over-copper/#3Com%203c996BT:|outline offers the datapoint of 436 MBits/sec in an oldish dell optiplex ( old being whenever p3 500 mhz machines were still made)
So, am i looking at a hardware limitation? driver quirk? I'm open to any suggestions.
I'll keep an eye on the web archives, but please CC me on any replies.
thanks ==rob
-- Rob Latham Mathematics and Computer Science Division A215 0178 EA2D B059 8CDF Argonne National Labs, IL USA B29D F333 664A 4280 315B - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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