32 or 64-bit cuda toolkit Which to download, 32 or 64-bit for cuda development toolkit?

I’m running 64-bit vista (and windows 7 on another computer) operating system, visual studio 2008 and 2010, both allow me to write 64-bit or 32-bit code. I don’t know what it means to get the 32bit or 64-bit version 3.2 cuda development toolkit: does getting the 64-bit mean I can only develop code that will run on computers running 64-bit operating system, or does it just mean that my development software runs in 64-bit, and I can choose to develop for either 32-bit or 64-bit users? This is very confusing. Thanks


Using 32 vs 64 means that you could dev. 32 or 64 applications. It should be possible to install both and develope for 32 and 64 bit.

Does anybody know if it’s really possible to install both versions? If so, are there two environment variables set to the different versions paths to be able to read out installation location using getenv() in matlab?


I think it’s enough to install only one. I have 64 bit and it includes 32 bit dll and lib files as well.
Compiler is the same and can generate 32 and 64 bit. The only big difference in Computing SDK is that 64 bit one have examples compiled for 64 bit target, that’s it

Is it possible to install only cuda toolkit 32 bits on a 64 bits computer ? and work only on 32 bits ?
Because i’ve got too many incompatibilities …

Yes it is.

64-bit drivers (if you are running 64-bit OS)

32-bit cuda toolkit

32-bit SDK

When you compile, you must compile as 32-bit application.

I didn’t fully understand. So does the 64bit toolkit contains also the 32bit, and thus able to compile 32bit apps?
What if I want to compile both 32bit and 64bit apps?

  1. If you have a 64 bit system you need to install the 64 bit gpu driver. this driver has compatibility for the 32 bit programs

  2. You can choose cuda library you install (32 bit or 64 bit).

If it is unclear just go with the 64 bit all and you are going to be able to program without problems.

@pasoleatis, thanks for replying, but you didn’t answer my question. I know about the driver and I installed the 64bits as someone previously recommended. But:

  1. Can I with the 64bit toolkit compile 32bit apps?

  2. If not, what do I need to do in order to compile both 32bit and 64bit on my computer?

Sorry, but I didn’t understand your sentence: “If it is unclear just go with the 64 bit all and you are going to be able to program without problems.”

  1. No. I had a long time ago XP + CUDA. I tried to compile the examples as 32 bit projects. It did not work.

  2. My guess is you have to install the 2 toolkits in different folders and make the appropriate links during compilation.


32-bit toolkit can compile 64 and 32-bit apps. 64-bit toolkit can compile 64 and 32-bit apps. this has been true for at least a year now.

Thanks for clearing it up, I tried to compile 32 bit codes with a 64 bit about 2 years ago.

Thanks again…