32 Bit CUDA on 64 Bit machine

Hi all,

I was wondering if there are any known issues with using the 32 Bit versions of the CUDA libraries on a 64 Bit machine? I need to link to 32 Bit libraries and thus want to use CUDA in 32 Bit, too.

My CUDA programs run very slow and results are incorrect.

The following is the setup:

  • 64 Bit Windows 7.
  • 64 Bit CUDA 2.3 drivers (190.38).
  • 32 Bit CUDA 2.3 SDK/Toolkit.

The same code runs very fast and gives correct results when running on a 64 Bit Linux with 64 Bit CUDA 2.3 SDK/Toolkit.

Any hints are appreciated!

Try more recent driver for win7. My program runs 20% slower on win7, but correct.

Thanks for your reply. Unfortunately, updating to the latest driver didn’t bring any improvement.

Still slow. Results are still wrong.

If there is no known issue with this mixed 32/64 Bit setup, I will skip installing the 64 Bit CUDA and instead start debugging.

The driver model on Vista imposes additional restrictions that reduce performance versus the Linux driver path. Also if you’re not checking all errors from CUDA API calls, make sure to do so.