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

See this stack overflow question Installing cuda 5 samples in Ubuntu 12.10.

1. Ubuntu 12 is not a supported Linux distro (yet). For reference see CUDA 5.0 Toolkit Release Notes And Errata

   ** Distributions Currently Supported

   Distribution       32 64  Kernel                 GCC         GLIBC        
   -----------------  -- --  ---------------------  ----------  -------------
   Fedora 16          X  X   3.1.0-7.fc16           4.6.2       2.14.90      
   ICC Compiler 12.1     X                                                   
   OpenSUSE 12.1         X   3.1.0-1.2-desktop      4.6.2       2.14.1       
   Red Hat RHEL 6.x      X   2.6.32-131.0.15.el6    4.4.5       2.12         
   Red Hat RHEL 5.5+     X   2.6.18-238.el5         4.1.2       2.5          
   SUSE SLES 11 SP2      X   3.0.13-0.27-pae        4.3.4       2.11.3       
   SUSE SLES 11.1     X  X   2.6.32.12-0.7-pae      4.3.4       2.11.1       
   Ubuntu 11.10       X  X   3.0.0-19-generic-pae   4.6.1       2.13         
   Ubuntu 10.04       X  X   2.6.35-23-generic      4.4.5       2.12.1    
   

2. If you want to do it run on Ubuntu 12 anyway then see answer of rpardo. It looks like this distro instead of installing 64 bit libraries to /usr/lib64 installs them to /usr/lib/x86_64-linux-gnu/

I'd suggest searching for all instances of libcuda.so and libnvidia-ml.so on the system. Since the driver doesn't support this distro it might have installed libraries to a path that is not pointed by LD_LIBRARY_PATH. Then move the libraries around and/or change the LD_LIBRARY_PATH to point to this location (it should be the first path on the left). Then retry nvidia-smi or deviceQuery

Good luck