Well, the comparison to 3d accelerators is valid and it isn't. Its the same kind of idea, a seperate focused device that will take the load off the processor and do it better at the same time. But this isn't a graphics card. And it isn't 1996. There's a very different climate out there now.
I remember when my friend came over and played dark force II: jedi knight on my PC with a 3dfx voodoo and my parents with integrated graphics. He said "The graphics are good on that other one...but they're AMAZING on yours." Now JK looks pretty horrible these days, but he was right. 256 colors at 320x240 and bad framerates versus 16bit at 640x480 and smooth framerates. It was night and day. I grumbled about having another expensive component to buy, but it certainly offered a very tangible benefit. And it wasn't long before 3d accelerators weren't even an option anymore. The 3d accelerator was probably the biggest thing to happen to PC gaming, I'd say in its entire history. Only the sound card would come close IMO.
Is the physics card going to provide this same night and day difference? I don't know. But before you answer consider that even with the 3d accelerator there WAS a transition period. Everyone here talks about exploding buildings that crumble, endless 3d objects bouncing all over the place, etc. But if this thing wants to be accepted games can't REQUIRE it, at least not right away. So initially we're going to have to have software physics tandem along with it, and its going to cater mostly to the lowest common denominator.
Whether people are going to see the difference between relatively simple physics being dumped onto the now readily available second CPU core and the presumably superficial enhancements offered with the PPU remains to be seen. I say superficial because they probably wouldn't want to break the game for non-PPU folks or lengthen already very long development times by changing the game signifigantly with enchanced physics, so we can probably assume that we'll see the extra PPU power used on boring extra things. You're not going to see 25 boulders instead of 3 rolling at you with the PPU. You'll probably just see some pebbles that wouldn't make any difference in the completion of the level. This is just a guess based on past precidents though.
Also of note...there's no directPhyiscs or OpenPL to program for to my knowledge. Part of the reason 3d accelerators took off is was it was easy enough for developers to put them to use...indeed it became easier TO use them to not use them. But then again, ageia could just be the "Glide" for PPUs.
I don't know. I could see the PPU being useful. But I'm not sure it was introduced at the right time to be successful. Developers have been happily shoveling the workload onto the GPU for a few years now since CPU speeds have lost their speed of growth. Now they have double the speed, with some real work being required to harness it. Is there really room for another processor at the developers table? It looks like we're seeing both the developers and Ageia waiting for the other to flinch right now. There's a few games said to use it on the horizon, but the part isn't even out there.
Time will tell though. It might only take a few killer apps to get the market momentum going. I think price will play a big part. If it costs between $50-100 and there's a handful of games that really benefit from it I could see it getting a solid install base and taking off from there. If it costs $200-300 or something I think its completely doomed unless they can trick microsoft into slipping it into the vista system requirements or something.
