I tried the new nfe driver on my Tyan S2895 running the amd64 port,
and it seems to do OK for light traffic, but sustained NFS traffic
causes it to lock up for 60 seconds, work for a few seconds, then lock
up for another 60 seconds, etc...

Building a NetBSD kernel on the S2895 with the source on a NFS server
(OBJDIR on a local filesystem) triggers the problem for me. I'm
pinging the NFS server while the build is running, and tcpdump shows
that the ping packets are making it out, but nfe isn't seeing the
replies.
-- 
Name: Dave Huang         |  Mammal, mammal / their names are called /
INet: khym@azeotrope.org |  they raise a paw / the bat, the cat /
FurryMUCK: Dahan         |  dolphin and dog / koala bear and hog -- TMBG
Dahan: Hani G Y+C 30 Y++ L+++ W- C++ T++ A+ E+ S++ V++ F- Q+++ P+ B+ PA+ PL++