title: no CUDA-capable device is detected (using ubuntu 12.04.4 server)
body: <p>I recently installed the cuda toolkit 5.5 with driver 331.67 (I have a GeForce GTX 680). For some reason, I cannot run any of the test scrips:</p>
  
  <pre><code>$./NVIDIA_CUDA-5.5_Samples/1_Utilities/deviceQuery/deviceQuery 
  ./NVIDIA_CUDA-5.5_Samples/1_Utilities/deviceQuery/deviceQuery Starting...
  
  CUDA Device Query (Runtime API) version (CUDART static linking)
  
  cudaGetDeviceCount returned 38
  -&gt; no CUDA-capable device is detected
  Result = FAIL
  </code></pre>
  
  <p>I followed the steps on the "getting started guide" here</p>
  
  <p><a href="http://docs.nvidia.com/cuda/cuda-getting-started-guide-for-linux/">http://docs.nvidia.com/cuda/cuda-getting-started-guide-for-linux/</a></p>
  
  <p>and made a script to create the character device files at startup (as I am running the server edition of Ubuntu such graphics files aren't created by default):</p>
  
  <pre><code>$ls -l /dev/nvidia*
  crw-rw-rw- 1 root root 195,   0 Apr 11 17:29 /dev/nvidia0
  crw-rw-rw- 1 root root 195, 255 Apr 11 17:29 /dev/nvidiactl
  </code></pre>
  
  <p>The output for executing the command <code>nvidia-smi -a</code> is (for both normal user and root user):</p>
  
  <pre><code>Failed to initialize NVML: Unknown Error
  </code></pre>
  
  <p>Here is some info on the nvidia module</p>
  
  <pre><code>$ lsmod | grep nvidia
  nvidia              11335080  0 
  $ modinfo nvidia
  filename:       /lib/modules/3.11.0-17-generic/updates/dkms/nvidia.ko
  alias:          char-major-195-*
  version:        331.67
  supported:      external
  license:        NVIDIA
  ...
  ...
  </code></pre>
  
  <p>Any suggestions ? Thanks.</p>
  
  <p><strong>EDIT #1</strong> 
  I tried downgrading to driver 319.76:</p>
  
  <pre><code>$ modinfo nvidia
  filename:       /lib/modules/3.11.0-17-generic/updates/dkms/nvidia.ko
  alias:          char-major-195-*
  version:        319.76
  supported:      external
  ...
  </code></pre>
  
  <p>Now when I run <code>nvidia-smi -a</code> I get the following:</p>
  
  <pre><code>NVIDIA: API mismatch: the NVIDIA kernel module has version 304.116,
  but this NVIDIA driver component has version 319.76.  Please make
  sure that the kernel module and all NVIDIA driver components
  have the same version.
  Failed to initialize NVML: Unknown Error
  </code></pre>
  
  <p>I installed the <code>nvidia-current-updates</code> and <code>nvidia-settings-updates</code> packages from the repos before installing the driver file and I guess that's where the conflicting arose. I have not found a solution, but this is one step closer I think. Here is the result of <code>modprobe -l | grep nvidia</code></p>
  
  <pre><code>kernel/drivers/video/nvidia/nvidiafb.ko
  kernel/drivers/net/ethernet/nvidia/forcedeth.ko
  updates/dkms/nvidia.ko
  updates/dkms/nvidia_304_updates.k
  </code></pre>