--- Danial Thom <[EMAIL PROTECTED]> wrote: > You couldn't do 100Mb/s with em on a 100Mb/s line > with min packets, because there are gaps between > packets so its impossible.
Thanks for the detailed reply Danial. By 100Mbps I mean line-rate: 148809 packets/sec for 64-byte Ethernet frames + IPG and preamble appended. The 10/100 fxp NIC is on straight PCI-33. The 1000 em NIC is on PCI-Express x1. It can do 100Mbps line-rate (148809pps) in 100Mbps mode. In 1000Mbps mode it can do ~700Kpps, so the bottleneck isn't the FreeBSD IP stack. > Realize that fxp parts are only 32bit/33mhz so > the bus is a factor. Although its a 1Gb/s bus, > thats only when bursting, so its really > substantially less. With shorter packets you > have more setups and I/O and therefore more > overhead on the bus. Yes indeed. > fxp performs similarly to an em controller when > they are both on a 32bit/33mhz bus in Freebsd 4.x. > 5.x is about 20% slower than 4.x, but I expect the > drivers to be about the same for 5.x as well. Thanks for that. I realize that comparing a PCI-33 NIC to a PCI-Express NIC isn't fair. I don't have a PCI-33 Gig NIC - why I need outside info. > Are you using a traffic generator, or are you > relying on some server to return packets? Ixia traffic generator. > We have customers with fxp interfaces on freebsd > 4.x pushing 90Mb/s+ (while doing a lot of other > processing also), so its certainly possible. Yes, I can get 100Mbps using larger frames on the fxp - but it's the performance limit on the smallest frames, with the largest per-frame overhead, that I'm trying to discover. Thanks again for the reply - I appreciate the info. Paul. __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com _______________________________________________ email@example.com mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "[EMAIL PROTECTED]"