Physics Accelerators and Gamer's PCs

Physics accelerators to me sound like the next big thing. However is there room for them, given gamers already stretched purse? Or do people really have that much disposable income?

Physics in games weak at the moment, with most objects behaving like a collection of rigid bodies. 3D cards have given us objects with thousands of polygons, but left the objects largely static. Deformation mostly consists of rubbish looking explosions - which become animations - and set pieces. Even the much vanted HalfLife 2 has only moved the bar a little - arguably no where technically as the Havok engine had been used elsewhere in Painkiller and the like. What it did do was make gamers realize how much they like bashing things, and give all those calculations real shape. HL2 still does not really allow walls to be smashed away, or every item to be crushed, pulled apart or destroyed. Garys mod shows how much the engine suffers if you your imagination run wild, quickly bringing your ninja gaming rig to its knees.

HL2 was, however, a glimpse at what could be if machines could deal better with the problem. Physics is something most people take for granted. Even the most simple games usually have to obey some bastardisation of it just to be playable. It just sits in the background, making things feel right.

So PPUs are a great thing. My issue is do I really want/need to buy another card to do it? A top end gaming rig will have a sound card, a graphics card, and a physics processing unit in it. To me that is too much. I think one will have to go. Graphics cards are pretty much here to stay - CPUs simply cannot keep up. On board sound is getting better, and to me an obvious candidate for removal.

However GPUs were not always transform and lighting engines. Originally they were glorified texture mappers. Then nVidia changed it by adding T&L, and now that is the norm. To me a PPU will be so critical for next (or but one!) generation games, the GPU is the only place to do this. The GPU is maxx'ing out faster than most realize in terms of what is required with out a fundamental shift. Carmack's Doom 3 bumpmapping has shown that model meshes many times more complex than older generations can be rendered with ease. Resolutions are getting up to limits of the human eye, and soon the manufacturers are going to need a new trick.

PCI Express is bidirectional, so suddenly getting things back out of the card has become possible. This allows the CPU to offload more than ever before. Soon a PC is going to look like a console, with custom hardware to do all the laborious bits. Unlike a console it will probably have a massively overspecced CPU...

The first generation of PPUs may well go like the first round of the 3D wars, when 3Dfx had a massively superior card, making gamers willing to pay the difference. Then the existing GFX manufacturers will move in and clean up with integrated solution. After all whats the point of blowing a wall up on one card, then transfering the data to the other card to be rendered? Makes no sense to me.

So I suspect the idea of a standalone PPU will be a shortlived idea - possibly never really getting off the ground as a seperate entity.

Which brings me round to another annoyance. nVidia's Soundstorm or lack of it. Integrated into the motherboard, this made having an add on soundcard totally unnecessary for nForce2 owners. Then suddenly its not there any more, and the next gen only have grown up features like Raid. My own personal conspiracy theory is that it was too good, and Creative gave nVidia a huge wad of money to make it "disappear" for a bit. I expect that nVidia were also happy since it didn't really help their cause of getting maximum sponduliks out of the punter. The next Soundstorm will probably be an add-on card. So everyone will be happy.

Except me.

You see I think the sound card should also be on the GPU. The GPU then becomes a World Processing Unit. Other than freeing slots, producing less heat etc, it has some practical programming benefits. If the WPU (hey pretty snappy) had a PPU, GPU and SPU (sound processing unit) in one, it could share the 3D scene info. Blowing up an object would automatically create 3d sounds as they bounced off the walls, whilst the rendering part of the chip made sure they all look right. All the CPU need do is periodically inspect the items and give nudges to things at opportune times. The final step of this virtual bliss would be to create a cross platform API for manipulating this scene - OpenGL has a scene API that might just be extended to match this new world.

Unfortunately I expect that manufacturer desperation will be the only thing that makes this happen, but if it did Linux and Mac gaming would become a whole lot better.

Comments

Anonymous said…
I know of more than one scientist implementing very advanced physics simulations on the GPU. I don't really see ANY other place to do this today. The only advantage I see in using a PPU is the extra memory bandwidth this will add in the PC.

The idea about implementing a global sound processing is very interesting. Perhaps this will be possible on new multicore GPU's.
Anonymous said…
I may be wrong in assuming this, but it'd be great if a PPU or WPU were made, just so the current load can be taken off the CPU and it can be put to work on AI routines and procedures for games.

Of course, we'd also be looking forward to an AIPU/APU/IPU in the near future ;)
Anonymous said…
The game "Soldner" demonstrates what a huge load large maps with completely destructible environment can add to a game. While a minor success (too many bugs) the ppl who played it have a hard time going back to a game where you can't blow everything up and make holes in the ground. However the largest load was on the server, requiring a computer far more powerful than the fastest desktop PC to run a fully populated server (Dual CPU, 4GB ram etc).

Putting the PPU and sound on the vidcard means even servers will require a high end vid card to run a decent game, which is counter productive. They don't need graphics, sound etc, just physics processing. With DUAL processor computer soon to become the "average" (for a gamer lol), using one CPU for physics makes much more sense than having dedicated add in cards for physics.
Anonymous said…
And why not move everything to the CPU and lessen the heat and slots even more... And in that line of thoughts we will arive to Playstation2 and the Cell processor. I think that in the future things will get even more fragmented like it or not. We might even have A.I. accelerator. And about the capabilities of GPUs reaching the human eyes limits I only can say go and ophthalmologist. Did not want to be rude as you did not want to be dumb I suppose...
Dooferlad said…
The nVidia Soundstorm went away because of the Dolby Digital encoder - nVidia had to pay rolalties for every board sold with it on. I don't know if you have to pay for AC97, but since it has replaced Soundstorm on the boards my guess is either you don't, or you don't pay a lot.
Alex Powell said…
Interesting comments. Putting a PPU in a server is not something I considered, but I suspect that when they get accelerated, if high end GPUs are what needed in the server, then thats where they will put them. Servers are expensive and often contain unusual cards, so there could be a market there. They do not sell in the volumes required to sustain low cost cards.

I think that a CPU is unfortunately an outdated concept for this stuff. GPUs are really speciallist CPUs already. The Cell chip is a middle of the road solution, neither CPU or GPU, but can look like either. See previous posts for my feelings on that chip.

Dolby licensing. Figures, though why they couldn't just pull it out I don't know...
Anonymous said…
Welcome to the world of IP:

- MS paid for Nvidia's original Dolby License so they could use Soundstorm on the Xbox. XBox 2 doesn't have nvidia, no more soundstorm. Not sure what sony's doing for sound on PS3.

- Aureal was a company that did realistic sound modelling using 3D geometry info. They had a custom API to submit the geometry data to the sound card. They also had the best 3D positional sound in the industry. Unfortunately they went out of business and was bought by Creative - who will NOT be licensing that IP to anyone. I wouldn't count on realistic sound modelling using geometry data anytime soon.

Personally, the whole concept of a PPU sounds great, but the details are nasty. Unlike graphics, you cannot really scale "realism" between those without and those with a PPU. It changes the entire gameplay dynamic. So, you have essentially 3 choices: use physics for things that don't matter to the gameplay, use a small enough amount of physics processing that it can still be done on a high end CPU with reasonable frame rates, or you REQUIRE a PPU to play. I think eventually dual and multi-core CPUs are a much better answer.
Anonymous said…
Duel CPUs are not that viable of an answer to the physics problem, CPUs do not have the parallel architect to do physics well; it would be like comparing a car with a V4 (CPU) to one with a supercharged V8 (PPU). As for the idea of a WPU or card, it’s an interesting idea. As for the PPU, I heard that the company that makes the PhysX chip are tying to get them placed on graphics cards and/or motherboards.

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