How to set specific GPU to use Physx and to not How to set specific GPU to use Physx and


I have just updated to the new PhysX graphics cards drivers. The drivers are so far very nice minus a refresh rate issue that is fixable with a regedit.

My question is people have said that you can have two separate GPU by Nvidia and have your secondary set as the Physx only card. Can someone score me a link or tell me where do you set which GPU is the Physx card and that the other is to be used only for Rendering.

I have a 9800 GX2 as my main and just picked up a 8800 GT for my Physx card. I have my second card installed but where do you tell the system to not use Physx on my 9800 GX2 and to use it on my 8800 GT?


I am to understand that full support with SLI is to be coming at a later stage. Presumably this applies also to 9800GX2 video cards. I could be wrong, maybe someone can correct me.

Here is a screenshot of where you change the option to select the second video card for physx.

Awesome thank you so much. Hmm wierd I guess the 8800 GT is no compatible or some how I have not installed it correctly?? I do not get the option as in your pic, it is not their. I have windows vista 64 ultimate, and when I added the 8800 GT it found the hard ware no prob and it is installed.

Maybe I will try to re install other wise its a return and I will get the 9600 gt like you or get a 9800 gt.

Your 8800GT is NOT the problem.

I expect that if you were to run with your 9800GX2 in single GPU mode then it should work with your current hardware. I don’t own a 9800GX2 so am not familiar with the settings. If there is an option in the nvidia control panel to disable SLI then give that a try.

Here is an excerpt from an interview on

Yeah, definitely check the information that stickywulf quoted, until a monitor is attached to the other card and the desktop is extended to it you won’t even see the select gpu button.

Thanks for all the great info, this tech is new so I know things are hard to come by and there will be issues. Big ups for your help.

Unfortenatly I tried over and over again and I think unless I plug another monitor (gona try that next) it will not work. As a weird side effect I have lost the SLI option in the control panel once I installed the second card 8800 GT? I did disable SLI first but once I install the other card the SLI option is nuked and I stilll can not choose any option.

I guess I just have to wait for the next drivers, I think I will hold on to my 8800 GT for I got it at a good price.

Thanks again.

Ya I think your right I am gona try it next with a monitor hooked up to see what it does, all well might have to wait for the next drivers for my pimp set up. Or I guess I could trade my BFG 9800 GX2 for a 280 but I love the HDMI output on my current all well. I think I will wait.


I have a 9600GT as my primary display and an 8500GT which I hope to use as a Physx board. The problem is, after installing the CUDA drivers, I see absolutely nothing different in Vista. I have no option of which card I would like to use for PhysX and indeed no mention of PhysX at all. Can someone please explain in idiots terms what I need to do to get to that screen which was posted earlier in the thread.

It would be much appreciated.