Re: nForce 4 corrupting data written to HDD
In my case I have confirmed that power-supply voltages and all temperatures are well within operational limits.
I put the mainboard in a spare case and booted Knoppix (32-bit 2.6 kernel). I started by copy and compare test using the VMware guest image files that have exhibited corruption in the past. I let it run for a little over 12 hours (43 passes) and only a single file was corrupted. The corruption consisted of three bytes in a single 32-bit word being incorrect.
I then installed Fedora Core 6 (what was being used in the installation where the problem was first noticed). The stock FC6 kernel has problems driving the SATA controller. It reports errors then resets the controller and programs the drives to the slowest speed. It continues doing that after transferring what appears to be a couple of megabytes of data. I'm going to try and find time to build a kernel.org kernel (which is what I was using in the original installation).
Note that the disks are different than in the original installation which might explain why it is more difficult to trigger the failure.