Blog FeedGetting Physical with Graphics
By now, word of AGEIA’s “PhysX” Physics Processing Unit has reached all corners of the globe. Indeed, Epic has announced that the next Unreal games will be able to make use of it, FutureMark has licensed the technology for future benchmark programs, and the tech demos provided have shown some impressive performance. After reading an interesting article on X-bit Labs just the other day though, it looks like AGEIA’s attempt at controlling an as-yet uninhabited section of the market could be at an end pretty soon.
ATI Technologies says that its chips are already capable of processing physics and it is only a matter of time for the graphics giant to enable the capability on commercially shipped units.
It goes on to say that graphics cards all the way back to the Radeon 9700 PRO are capable of physics processing, and since then, ATI has sold a lot of cards. While I can’t imagine these being as fast as a dedicated physics processor, graphics chips are hugely more complicated than desktop CPUs, and would probably be quite capable. It would also satisfy those who can’t stand the thought of needing yet another piece of equipment to get the most out of their games.
I believe a PPU has a place in the market as long as it’s physics performance is greater than a typical CPU by several orders of magnitude, as AGEIA has shown to be the case at the moment. That said, even if a graphics card could muster 50% of that performance, I think a dedicated PPU would have a very difficult time finding a place in the homes of anyone but the most dedicated and wealthy gamers. And even they could well find it superfluous, if they need the PCI slots.
9th October | Reply
Is this the same ATI that promised us a 32 pixel pipeline and gave us 16? Or the same ATI that still has yet to release its video card this round? While it sounds great I highly doubt ATI just as a magical section of video card they can “unlock” that will start processing physics like a PPU.
If their chips are already capable it does not mean 1. they are built for/good at it or 2. you can use physics processing without video processing having to scale down. If say you could use an old ATI card and ’switch’ it to physics mode then I might be interesting. It would be like a free physics card when you upgrade your video card.
Pardon me if I am hostile towards it. ATI has burned me in the past and just not delivered in the present.
9th October | Reply
If their chips are already capable it does not mean 1. they are built for/good at it or 2. you can use physics processing without video processing having to scale down.
The same can be said with regular CPUs. They aren’t built for/good at it, and using them for physics in games takes away processing power that could be used for other things. But you need to remember that GPUs are a lot more complex and it appears as they they would do a better job at physics processing than a CPU would. Plus, at the moment, we’re finding that with these stupidly powerful graphics cards, people are CPU-limited in most games.
So if we’re CPU limited, it’d be less trouble to take some untapped power from the GPU and put it towards physics calculations, so as to free the CPU from having to do them. And all this without having to spend $250 US on a separate physics card. I think it sounds promising, and if ATI can do it I don’t see why Nvidia can’t as well. Hell, maybe it means AGEIA could do the reverse and start processing graphics themselves.
10th October | Reply
Chris and I discussed this over IM but my position on the subject can pretty much be broken down to this:
Realistic physics in games is an overblown concept and there’s more important things to work on
Seriously, I really don’t care about physics in games that much; they’re already fine. I’m more in favour of letting the developers determine what I can or cannot do in a game than incorporating the facilities that could potentially allow me to break the game. This is perhaps going a bit too far but consider the FPS, Red Faction, and it’s Geomod engine that allowed the player to deform the environment. Originally an exciting concept it was found to be rather dull in practice because the player was only free to destroy aspects of the level that had been “marked” as destructible. A complete implementation of physics in a game would allow the player to destroy absolutely anything in much the way that we imagined that the Geomod engine would. In practice, however, I think that this is “a bad thing” as it will make it much easier for the player to take paths that weren’t intended and, therefore, potentially break the game. Freedom of choice is great and all but there needs to be something fun at the end of each choice and that requires advanced knowledge of all the possibilities.
My position is that games need to focus more on other areas, such as the Artificial Intelligence of the Non-Player Characters in a game, be they enemies in a FPS, characters to interact with in an RPG, or troops under your “control” in an RTS. Improving, for example, the path-finding abilities of troops in an RTS would add dramatically more to the overall gaming experience than realistic (or distorted) physics. Once developers have sorted out core aspects of their games, then they can play with the physics as much as they like for all I care. Just don’t be surprised if the end results aren’t all that impressive…
As for ATI, I don’t much care. Making efficient use of a computer’s resources is important and therefore I fully support the use of the GPU for performing such calculations if it has the spare capacity. It is, however, up to both developers and ATI to demonstrate how the GPU could be used and create the necessary drivers and libraries to make use of them. Until this happens then this announcement is nothing more than hot air.
11th October | Reply
A PPU for “Dig Dug” would make quite the interesting game indeed.
12th October | Reply
Well, I should probably make note that ATI has done some actual demonstrations of the technology and it looks quite interesting. The general idea behind it though, is that GPUs can be used for more than just graphics. Perhaps they could use them for AI computations as well. It depends on what kind of programming works better on a GPU instead of a CPU.
Granted, at the moment, the ideas seem to be for dual card solutions - one GPU to process the graphics, one to process the physics, etc… but I think it’s a move in a really fascinating direction. We could end up with “gaming” cards which not only do graphics, but also Physics and AI calculations as well. We have multi-core CPUs now… we could end up with multi-core GPUs, so you could have it all on one card. I’m not sure if that’s exactly the best idea, but it is an interesting one to think about.
13th October | Reply
Whether it is impressive or not one thing this does is validate Ageia’s direction. Now that a big mover like ATI is showing interest (or perhaps feels threatened) in dedicated physics I think many game developers will make use of a PPU. More-so than if it was Ageia alone making these ‘gimmick’ type devices.
It will probably end up like most computer components. Enthusiast and mid-range. A dedicated PPU would most definitly have more power than a GPU split between graphics and physics. So the Enthusiast market would be more likely to have 2 cards. However, if ATI (and you can bet Nvidia will follow) can swing a good Physics processing on their card I bet you’ll find a lot of people using it for midrange systems.
Overall this means after a couple years the majority of PC gamers will have something in their machine capable of running physics beyond just a few hundred objects in the level. This opens new doors for developers and the kind of games we make. Good stuff.
I disagree with Kelmon as well. I feel physics can enhance a game experience. While if you gave me the choice of AI or Physics I would definitly go with AI (I would love an AIPU) I will not reject some fantastic game mechanics and visuals just because I am not getting other things.