Comment 16 for bug 130075

More testing with these boards and latest Gutsy (2.6.22-14-generic x86) yields the following observations above and beyond those previously reported:

1. It still locks up under Gutsy latest (I can't tell any change between 2.6.22-12 and 2.6.22-14). Someone should probably report this as a problem to the kernel mailing list or whoever maintains the forcedeth driver.

2. It isn't hardware though. I booted a XenSource 4.0.1 install in the system (partly to test a different distro and partly to see if they had support for these nforce boards because SuperMicro makes a dual socket Barcelona board based on the big brother workstation version of this NF570 chipset that looks fairly tasty except it has the same dual nforce LAN setup). The Xen kernel gives the same spurious "too many iterations" but unlike Ubuntu, refused to lock up even after hours of serious abuse. XenSource's kernel is a stripped down version of 2.6.18 based on CentOS 4.4 I believe.

3. FWIW, the cheap PCIe Marvell 88E8053 based NICs from Rosewill mentioned earlier do seem to work reliably in Gutsy (although the requisite sky2 module is a nightmare on other platforms including Xen). I've transfered TB of data both ways with it via NFS in Gutsy with no problem other than high CPU usage (see next item).

4. Both the Marvell and the Nforce hardware can't hold a candle to Intel as far as CPU offloading goes. For troubleshooting this problem, I used an old 1.8Ghz P4 (single core) system running Feisty with an intel 82547EI gigabit adapter on the MB - it never goes above 50% CPU usage serving or pulling at 1Gbps - whereas the Marvell and Nforce solutions routinely use most of what a 2.1GHz dual core Athlon 64 X2 system has to offer, just to run iperf! I know I could make this CPU usage go down by enabling jumbo frames across the board, but that introduces a whole other list of compatibility problems I don't want to face.

Long story short - you get what you pay for I guess. It's a shame, because the 6 channel SATA2 controller on these Nforce 570 boards seems to perform quite nicely and reliably using mdadm and RAID5 or RAID6. If the dual nforce LAN worked, the board would be quite a steal for $80 and another $80 or so for a fast Athlon X2 proc - but unfortunately, it doesn't.