@thomthom said:

Turning of Hardware Acceleration makes SketchUp not use the graphic cards at all.

I kinda figured that, but it works, and both cards are in use.
<shrug>

Do you have a recommendation for additional scenarios to use SketchUp?

1. Use just one nVidia graphics card at a time. (requiring a change of settings)
2. Turn off Hardware Acceleration. (thus negating the GPU advantage)
3. .....

Well here is some interesting development(s)-

First, I updated my nVidia drivers to the latest on the website (178.13)

After a full restart, I tried Sketchup, and the performance was the same.
(using both vid cards)

However, leaving both cards on, and turning off Hardware Acceleration + Fast Feedback (in SketchUp), it starts to respond (more) normally. Not perfect, but LOADS better.

Very interesting.

Thanks everyone, for help in pointing to the drivers for blame, and not to the fabulous SketchUp team........

@thomthom said:

any OpenGL application became dead slow. DirectX worked fine.

Does SketchUp support DirectX?

@anssi said:

Officially SU does still not support multiple monitors.

Bummer.

Thanks very much for the responses!!!

@vik1786 said:

can someone help me??

I installed a second video card, and now Sketchup consumes 1/2 of my quad-core CPU.

My solution is to only use one video card during use of Sketchup.
I found that if I reduce my desktop from 4 monitors to 2 (just one video card in use), then start Sketchup, it performs normally.

Hope that helps.

I've got two geForce graphics cards in my system -- one PCI-EX, one PCI. When I've got the PCI one enabled, and my Windows (Vista, SP1) Desktop spread across both cards' monitors, after loading Sketchup, or a model in Sketchup, up to 50% of the processor will be consumed by SketchUp.
Process Explorer reports that half of that is taken by the nvidia driver, which is confirmed, when I turn off one of the cards (doesn't matter which) -- when i reboot Sketchup with only one video card enabled, it performs normally.

I am also using the 3D Connexion SpaceNavigator PE, with the latest version of the Sketchup plugin. (3.2.8?)
And the latest versions of Sketchup, and Vista.

I know how to work-around -- just use one-half of my monitor 'array' -- but I figured you'll want to know about it.....

Thanks for all your work, SketchUp team!!!