decreasing interrupt CPU load

[Oleg Gawriloff]

Hello!

Currently we have router on FreeBSD 4.10-R on SMP 2*PIII 1Ghz. 5sec average 
traffic trhough fxp on Intel 82550 is about 12kpps (26Mbit/sec). CPU Load on 
interrupts shown in top and systat -v 1 always above 40%. We've tried to 
enable polling with HZ=1000, but cpu load does not change, instead round 
trip time increased from 1ms to 20ms. Also we've tried link0, no success. Is 
any other options to decrease interrupt cpu load? May be enabling fast 
forwarding, change fxp to em or bge NIC? Is there exist any drawbacks from 
enabling fast forwarding?

With best regards, Oleg Gawriloff.