Today I finally got my second 8800GT card installed to my system and all settings configured. Unfortunately, my joy didn't last long, as after solving the issue with both kmalloc and overheating problems due to the NVIDIA driver not spinning up the fan on other card, I faced the problem I wasn't able to solve.
To test my rig I launched the Unigine tests -- Heaven and Tropics. Quite soon I saw that this led to my X freezing up. My mouse cursor would move but nothing else gets updated on the screen. After a while it might again run for some seconds, then freeze again. It's possible to ssh in, and if the tests are killed soon enough (before the third freeze in a row) the control of X returns after a short amount of time.
If I go to check DMESG, I find these:
[ 404.517576] NVRM: Xid (0002:00): 13, 0001 00000000 00005097 00000680 0080027 00000100
[ 417.883918] NVRM: Xid (0002:00): 13, 0001 00000000 00005097 000015e0 00000000 0000100
[ 431.507992] NVRM: Xid (0002:00): 13, 0001 00000000 00005097 00000680 000700b4 0000100
[ 604.991138] NVRM: Xid (0002:00): 13, 0001 00000000 00005097 00000680 00030052 0000100
[ 648.393519] NVRM: Xid (0002:00): 13, 0001 00000000 00005097 00000680 000100ea 0000100
It seems that these errors are connected to my second GPU. However, that's exactly the card I have been running for some time now already, so it's a bit more over suspicions than the one I plugged in today.
As the topic tells, I'm running the newest NVIDIA drivers. Xorg-server is 1.7.6 and kernel 2.6.32. I'm running Gentoo.
Any ideas? I have checked and tested most of the things listed in the sticky.