Use only one of two GPU cards on a PC


I just installed a PC with two NVIDIA GPU cards, one is GTX 640 which is connected to display, the other is GTX Titan. Is there a way to configure this environment so that only the GTX Titan is used for computing?




A few weeks ago I saw the answer to the question on this forum, though I can not remember how to set the environment variables. Otherwise just use cudasetdevice(n) where n is 0 or 1 in your case.

The environment variable is called CUDA_VISIBLE_DEVICES


That explains how to set it up in a Linux environment, but the same can be done in Windows 7 via Control Panel -> System -> Advanced System Settings -> Advanced Tab -> Environment Variables. You’d probably want to make it a System variable as opposed to a User one. Similar procedure applies for Vista or Win XP if you’re using that.

You might also be able to accomplish the same in Windows by using the NVIDIA Control Panel – there should be a CUDA - GPUs feature that can be set to any/all/none of the GPUs currently in your system.