Re: 3Com 905C very slow (400Kbps)
Bogdan Costescu <[email protected]>
| Newsgroups | gmane.linux.drivers.vortex.devel |
|---|---|
| Message-ID | <Pine.LNX.4.44.0306041916040.20917-100000@kenzo.iwr.uni-heidelberg.de> |
On Wed, 4 Jun 2003, Florian Hackenberger wrote: > Well, I experienced an improved performance over the hub with the > realtek card, compared to the 3Com device. What do you call "improved" ? How do you measure it ? > What do you mean with media mismatch? Forcing at least one of the partners (card and switch) to a specific speed and duplex setting instead of letting both ends on auto/nway. Check the archives of this list... > If you compare the throughput colums, you'll notice that the P75 is MUCH > MUCH slower than the P4: Well, it's something like 7-8 years difference... > So here are the results from netperf P4=server > 87380 16384 16384 10.00 33.46 > P75=server > 87380 16384 16384 10.01 51.01 Well, 33 Mbit/s ~= 4 Mbyte/s which is much better than any figure you showed until now. While it's still far from the ~90Mbit/s theoretical maximum, it's probably because the system itself is slow. I do not have experience with such slow computers and PCI cards as to what they are able to sustain, as I wasn't doing networking stuff at that time... > DMA modes: mdma0 mdma1 *mdma2 If this drive is implicated in any transfer, it's probably slow. You could take it out of the measurements with something like copying a file from the P4 computer to /dev/null on the P-75 computer (assuming that P4 is NFS server and P-75 is NFS client) with something like: time cp /file/from/NFS/mounted/system /dev/null This will involve the disk on the P4 computer, but not the one on the P-75 computer. > But even with the crossover cable the transfer rate is under 700Kbps, > even without collisions and errors. It depends on what you call transfer rate: if you talk about disk-on-P4 to disk-on-P-75 then you might be limited by the disk speed, in which case you might want to put a better IDE controller in the P-75 computer. -- Bogdan Costescu IWR - Interdisziplinaeres Zentrum fuer Wissenschaftliches Rechnen Universitaet Heidelberg, INF 368, D-69120 Heidelberg, GERMANY Telephone: +49 6221 54 8869, Telefax: +49 6221 54 8868 E-mail: [email protected] _______________________________________________ vortex mailing list [email protected] http://www.scyld.com/mailman/listinfo/vortex