Use NVIDA card for CUDA, motherboard for video

I want use the motherboard as the primary display adapter and my NVIDIA graphics card as a dedicated CUDA processor. My first thought was to simply plug the monitor's VGA cable into the motherboard's VGA port and hope the BIOS was smart enough to use the on-board video as the display adapter when it booted. That didn't work. The BIOS must have detected the NVIDIA card and continued to use it as the display adapter. The next thing I looked for was a setting in the BIOS to tell it "don't use the the NVIDIA 560 as the display adapter, use the on-board video as the d开发者_StackOverflowisplay adapter". I search through the BIOS and the Web, but either this cannot be done or I cannot figure out how to do it. The mobo is a BIOSTAR TH67+ LGA 1155. Windows 7 OS.

RESULTS SUMMARY (from answers provided below) Enabling the Integrated Graphics Device (IGD) in the BIOS will allow the system to be driven from the on-board graphics even with the graphics card connected to the system bus. However, the graphics card cannot be used for CUDA processing. Windows will not enable graphics devices unless a monitor is attached to them. The normal driver stack cannot see them. Solution: use Linux, or attach a display to the graphics card but do not use it. The Tesla cards (GPGPU-only) are not recognized by Windows as graphics devices, so they don't suffer from this.

Also ,a newer BIOSTAR motherboard, the TZ68A+, supports the Virtu drivers which permit sophisticated simultaneous use of the graphics cards and on-board video.

Looking at the BIOS manual (.zip), the setting you probably want is Chipset -> North Bridge -> Initiate Graphics Adapter. Try setting it to IGD (Integrated Graphics Device).

I believe this will happen automatically as the native video won't support CUDA. After installing the SDK, if you run DeviceQuery, do you see more than one result?

I believe h67 allows coexistence of both integrated & dedicated GPU. Check out Lucid Virtu here http://www.lucidlogix.com/driverdownloads-virtu.html it allows switching GPUs on the fly. But I don't know if it affects CUDA device query. I never tried it on my rig, because its x58, I just heard it from tomshardware. Try it out and let us know. Lucid Virtu is definitely worth a try, its free, and it can cut you electric bill.