Shuffling the NIC's in their slots I got them from the same IRQ 10 (even the IDE controller was using IRQ 10). Now they are on different IRQ's of 10 and 12; but 10 is still shared with the IDE controller and one of the NIC's.
iperf now reports numbers in the 90-100Mbps range; so there's a bit of an improvement there. The reason I was concerned about speed is I was thinking of stuffing a couple drives on this and using it as a file server as well. And I like to know how well things are working; and that they are working as they are supposed to.
Ehhhh…. just went to test the cpu usage again; and I see that my rates have dropped back to the 10Mbps range again. Odd....
Oh - just realized if I start the iperf server on the main PC the rates are in the 8Mbps range; but if I start the iperf server on my pfSense box the rates are in the 100Mbps range. I'll take a closer look at the bios; maybe I missed something.