The obvious implication of the AEGIA acquisition is PhysX. In the same way that a typical GPU offloads graphic chores, a physics processing unit handles other tasks for the CPU. Like, say, realistically ripping fabric, calculating a flood of water and how it'll affect an environment, or simply tracking blades of grass when an avatar walks through a field.
Sounds great, but AEGIA was having a tough time selling folks on the notion of a separate physics processor add-in card (a PPU, if you will). It was a chicken-and-egg problem: How do you sell these $200-plus discrete cards without the games to show what the PPU can do if not enough developers were making enough good games that took advantage of it?
Back in the 90s, GLQuake and Tomb Raider sold users on the need for graphics cards. And now graphics cards will be selling the need for physics. By incorporating a PPU into the GX200 series, half that old issue is solved. With a wave of users buying one of these boards, developers have a much wider audience -- and a good excuse to add more realistic physics to their games, knowing the card exists.
Gaming remains the most obvious reason to buy these boards, though. But here are a few caveats before you run to a store (physical or virtual) for the best deals, though. Both cards are dual slot design (roughly the same size and girth as the 9800 GX2 cards) so make certain that you have a wide enough case (or don't mind cutting through the hard drive cage just to accommodate a graphics card. Even though the new card promises energy efficiency for the tasks at hand (according to Nvidia, 25 watts when idling in 2D mode and maxing out at 236 watts. In our test machine, the average Watt usage was 307 on the new card while the 8800GT kept cooler at 238 Watts.), you still need to make certain that your power supply is rigged to juice these boards. The GTX 260 requires two six-pin power connectors and the GTX 280 needs a six-pin and eight-pin connector. Crack your case before buying!
Which should you buy? I have a sneaking suspicion that the $400 model will be a more cost-effective speed boost. No definitive answer yet, though, since we are still awaiting a GTX 260 card to arrive in the offices. This page will