CUDA Runtime API error 38: no CUDA-capable device is detected

Question

The Situation

I have a 2 gpu server (Ubuntu 12.04) where I switched a Tesla C1060 with a GTX 670. Than I installed CUDA 5.0 over the 4.2. Afterwards I c

Answer 1

Try running the sample using sudo (or, you might do a 'sudo su', set LD_LIBRARY_PATH to the path of cuda libraries and run the sample while being root). Apparently, since you've probably installed CUDA 5.0 using sudo, the samples doesn't run with normal user. However, if you run a sample with root, then you'll be able to run samples with the regular user too! I've not yet restarted the system to see if samples work with normal user even after reboot, or each time you should run at least one CUDA application with root.

The problem might completely disappear if you install CUDA TookKit without using sudo.