To make sure that the CUDA (graphics card computation system) is working (currently only available on Taro and Pumpkin), check the following:
- When a new kernel is installed, the NVidia kernel driver also needs to be updated. This is done by re-running the NVidia driver installer in /root/CUDA_INSTALL. Run the one with the highest version number. You do not need to reinstall the entire CUDA toolkit after a kernel upgrade.
- The permissions on the /dev/nvidiactl and /dev/nvidia* devices needs to allow users to read them. Double-check them after a kernel upgrade and reinstall, as they have been known to unexpectedly change. To set these automatically create a file named nvidia in /etc/modprobe.d/ (if it isn't there already) any put this in it: (The NVreg_DeviceFileGID number should be the GID for the video group).
options nvidia NVreg_DeviceFileUID=0 NVreg_DeviceFileGID=98 NVreg_DeviceFileMode=0666
- Make sure the video group exists.
- Make sure users that want to use the CUDA system are in the video group.
- You do not need to run X to use the computational system (in the newer versions).
Checking the device
To run the graphical NVidia settings program run:
Xorg & nvidia-settings --display=$DISPLAY -crtl-display=:0
Where of course you know to set $DISPLAY to your current output device (i.e. your screen, which is a tunnel for ssh, something like localhost:14.0) That first command runs X in the background, which is needed for this program to access the card.
Another code is nvclock, this is 3rd party and beta and would allow overclocking. We don't use this for that reason.