Seriously a stupid question

I have been building and taking apart computers since 1996 (first grade no joke ;p), and my question is simple. If I have a 8800GT, and another card like the ati 3870 in the same computer what would happen? Could I run both cards at once, or will my motherboard shut one off or what.

Actually they should both run i believe. they will allow you to do a multimonitor setup in windows. so you can support up to 4 monitors.

One will basically shut off for direct 3d apps (games). so only the one that is designated as the primary card will render 3d. They will not scale to increase 3d rendering performance.

Windows XP has no problem running 2 different cards for multi-monitor setups (I always ran my GeForce 6800 AGP & Radeon 7200 PCI with no problems at all).
Vista only allows more than one graphics card if they both use the exact same driver.
Supposedly will be changed in the next version of Windows (v.7) to be back to being able to use different cards with separate drivers.
Would be nice.

Hey...your question is very valid.

The answer is YES you can run both the 8800GT and 3870 on the same mobo ... like I do.

But of course you can't simultaneously run both cards at the same time... you'll have to remove one to place the other.

Well I'm not sure it's practical at all, but I was thinking of something like game on one screen, hd movie/tv on the other. I'm not too sure though.

they ask questions like what kind of questions do stupid people ask?