I investigated the downclocking issues some more just now, since it seems to me that was one of nvidia's primary methods of conserving power at idling for the GT200 cards.
Through experimenting from forum tips, I discovered that the GTX280 will not downclock to 2D speeds (301/602/100 down from 602/1296/1107):
1) if you have a second monitor connected to it and enabled
2) if Steam is running
3) if windows live messenger is running
On my PC, if any one of those three were active, the 280 will not downclock. Apparently there are other non-3D programs that will also trigger this problem.
Seems like they still need to work out some kinks in the driver.
Through experimenting from forum tips, I discovered that the GTX280 will not downclock to 2D speeds (301/602/100 down from 602/1296/1107):
1) if you have a second monitor connected to it and enabled
2) if Steam is running
3) if windows live messenger is running
On my PC, if any one of those three were active, the 280 will not downclock. Apparently there are other non-3D programs that will also trigger this problem.
Seems like they still need to work out some kinks in the driver.