Network Performace

[Shawn Ramsey]

I am having some issues with network performance and am wondering if anyone has any suggestions... the box in question has 2 100BT interfaces, and an Intel (em driver) fiber Gigabit. The Gigabit connects to a switch, and the two fast-e are WAN connections to our ISP(s). This box seems to be using an awful lot of CPU cycles relative to the traffic it is pushing, which is around 65-70Mb inbound, and 20-30 Mb/outbound(on average), which seems to be about its limit. This is an Athlon XP 1500 box, 256MB RAM, top shows 90+% interrupt usage, CPU usually has about 5-10% idle. Gigabit is on a 32-bit bus, and Gigabit is on an IRQ shared with unused USB and onboard NIC which is also not used. Should I be able to push more than 100Mb sec with such a system? It is not doing anything else, no NAT, one IPFW rule. OS is FreeBSD 4.7-RELEASE.