Wow
I wrote a whole dissertation on this and didn't hit submit, lost it all .
Yes, we are running pavilions with AMD add in cards and On Board Intel Cards.
To sum up what I wrote,
I think the issue is when one card hands graphics off to the other or IE windows open with high graphics and animation the Physical memory gets spiked and invades Windows reserved space. Therefore Windows tries to keep operating by throttling the graphics down (basic mode).
By forcing the Graphics to be done by the GPU any communications coming from the Internet for rendering is going into system memory and that setting is actually telling windows NO YOU ARE NOT allowed to manage this within the space set aside in Physical Memory, and to keep from crashing it throttles it's own processes down to allow for the data to move through Memory. First to be sacrificed, the AREOS items.
I think if your running single monitor systems, check to see if there is an onboard video card that is properly disabled so windows doesn't think it has to support graphics to it, let Windows handle the rendering for IE so that it is allowed to manage the physical memory as designed, and any remote users with single monitors it is the same story. You need to let the operating system manage the physical memory and protect Windows operating space. Even if that means letting it page some stuff.
Then your dedicated software (you lazy gamers out there) will reserve it's space and anything else you do Windows will slow IT down rather than ITSELF.