Karl Hancock ([log in to unmask]) wrote: : Are there any options to put a 100BaseT card in an HP995 and a : HP9000 G40? For the 9K G40, there is an HP-PB 100BT card, the glossies should be somewhere on http://www.hp.com/. I'm not sure which HP-UX revisions are supported. I wouldn't expect 100 Mbit/s from it though. While 100BaseT ups the raw bandwidth on the wire, it does *nothing* to improve host efficiency of sending data (it keeps the same tiny MTU of Ethernet). So, if you have a system that takes 25% of the CPU to send at 10 Mbit/s, you will not get above 40 Mbit. I've not benchmarked an HP-PB 100BT card in a G40, but I would be surprised to see more than 40 Mbit/s from it. 30 might be more like it. Contrast that with HP-PB FDDI - FDDI ups the MTU by 3X or so, which makes sending bulk data *much* more efficient. There are some FDDI numbers for various system (not G40's though) in the netperf database (http://www.cup.hp.com/netperf/NetperfPage.html). Past experience has indicated that if you drop the MTU of FDDI to 1500 bytes, it will increase the CPU util of something like a TCP_STREAM test by 50%. You can use that when working-out a fudge factor for estimating 100BT performance. The HP-PB FDDI card also provides checksum offload, which is probably another 10% delta. Some of the features of that card (under HP-UX at least, I don't know if MPE uses them all) can be found at: ftp://www.cup.hp.com/dist/networking/briefs/copyavoid.ps.Z. That document has some data for G30 class CPU, and indicates that a G30 running HP-UX 9.0 could get ~57 Mbit/s using virtually all of the CPU. Take away the checksum offload, and it drops to 53 Mbit/s. Drop the MTU to 1500 bytes and increase the CPU util by 50% and you arrive at about 35 Mbit/s. Regardless of system I don't think anyone has clocked the HP-PB 100BT card over 50 Mbit/s. If someone manages it, the netperf database would love to see the result :) rick jones http://www.cup.hp.com/netperf/NetperfPage.html