Introduction

A little over a year ago, we first heard about a company called AGEIA whose goal was to bring high quality physics processing power to the desktop. Today they have succeeded in their mission. For a short while, systems with the PhysX PPU (physics processing unit) have been shipping from Dell, Alienware, and Falcon Northwest. Soon, PhysX add-in cards will be available in retail channels. Today, the very first PhysX accelerated game has been released: Tom Clancy's Ghost Recon Advanced Warfighter, and to top off the excitement, ASUS has given us an exclusive look at their hardware.

We have put together a couple benchmarks designed to illustrate the impact of AGEIA's PhysX technology on game performance, and we will certainly comment heavily on our experience while playing the game. The potential benefits have been discussed quite a bit over the past year, but now we finally get a taste of what the first PhysX accelerated games can do.

With NVIDIA and ATI starting to dip their toes into physics acceleration as well (with Havok FX and in-house demos of other technology), knowing the playing field is very important for all parties involved. Many developers and hardware manufacturers will definitely give this technology some time before jumping on the bandwagon, as should be expected. Will our exploration show enough added benefit for PhysX to be worth the investment?

Before we hit the numbers, we want to take another look at the technology behind the hardware.

AGEIA PhysX Technology and GPU Hardware
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  • Magnadoodle - Friday, May 5, 2006 - link

    Actually, if you look at this statement by Havok: http://www.firingsquad.com/news/newsarticle.asp?se..."> (Already linked)

    They also arrive at the conclusion that it is not a GPU bottleneck.

    Furthermore, the only thing the PPU seems to do in GRAW is render a couple of particles, while not improving or accelerating *at all* the processing of physics. This particle effect could have been processed very well by a GPU.

    I guess Anandtech didn't notice that the physics were exactly the same, thus pointing out the somewhat elicit nature of better physics.
  • DerekWilson - Friday, May 5, 2006 - link

    The havok guys did miss a few things pointed out earlier in the comments. Some destructable objects do break off into real persistant objects under PhysX -- like the dumpster lid and car doors. Also, the debris in the explosions is physically simulated rather than scripted. While I certainly agree that the end effect in these cases has no impact on "goodness", it is actually doing something.

    I'll certainly agree that "better physics" is kind of strange to think about. But it is really similar to how older games used to do 3D with canned animations. More realtime simulation opened up opportunities to do so many amazing things that just couldn't be done otherwise. This should extend well to physics.

    Also, regardless of how (or how efficiently) the developers did it, there's no denying that the game feels better with the hardware accelerated aspects. Whether they could have done the same thing on the CPU or GPU, they didn't.

    I'd still love to find a way to test the performance of this thing running the hardware physics on the CPU.
  • JumpyBL - Saturday, May 6, 2006 - link

    quote:

    Some destructable objects do break off into real persistant objects under PhysX -- like the dumpster lid and car doors.


    I see these same effects without PhysX.
  • DerekWilson - Saturday, May 6, 2006 - link

    When I play it without the PhysX hardware, doors just seem to pop open -- not fly off ... though I haven't exhaustively blown up every object -- there could be some cases where these types of things happen in software as well.
  • JumpyBL - Saturday, May 6, 2006 - link

    Shoot up the tires, car doors, etc enough and they come off. Same with the garbage can lid, throw a nade, it'll blow right off the container, all without a PPU.
  • Fenixgoon - Friday, May 5, 2006 - link

    how is the game going to "feel better" with a PPU when it slams your framerate down from buttery smooth to choppy? sorry, i'll take the FPS over any degree of better simulated physics, ESPECIALLY on a budget PC. i mean, look at the numbers! opteron minimum fps at 8x6 was 46, and with the PPU hardware it dropped to 12 - over a 75% decrease!!
  • DerekWilson - Friday, May 5, 2006 - link

    Note that the min framerate is much lower than the average -- with the majority of frames rolling along at average framerates, one or two frames that drop to an instantaneous 12-17fps isn't going to make the game feel choppy. The benchmark was fairly short, so even outliers have an impact on the average -- futher going to show that these minimum fps are not anything to worry about. At the same time, they aren't desierable either.

    Also, I would certainly not recommend this part to anyone but the hardcore enthusiast right now. People with slow graphics cards and processors would benefit much more by upgrading one or the other. In these early stages with little software support, the PPU will really only look attractive to people who already have very powerful systems and want something else to expand the capabilities.

    if you watch the videos, there's no noticable choppiness in the motion of the explosion. and I can say from gameplay experience that there's no noticeable mouse lag when things are exploding either. thus, with the added visual effects, it feels better. certainly a subjective analysis, but I hope that explains how I could get that impression.
  • mongo lloyd - Friday, May 5, 2006 - link

    You must be joking. Watching the videos, the PhysX one is WAY choppier compared to the software one. The PhysX video even halts for a split second, in a way that's more than noticeable; it's downright terrible.

    And the graphics/effect of the extra debris? Negligible. I've seen more videos from this game (for example: http://www.pcper.com/article.php?aid=245">http://www.pcper.com/article.php?aid=245 ) and the extra stuff with PhysX in this game is just not impressive or a big deal, and in some cases it's actually worse (like the URINATING walls and ground when shooting them). It's not realistic, it's not fun, not particularly cool, and it's slow.
  • Clauzii - Friday, May 5, 2006 - link

    I also think thats why we see such a massive FPS drop. We are trying to render, say, 100 times as many objects now?
  • DerekWilson - Friday, May 5, 2006 - link

    I was hoping we made this clear in the article ...

    While there is certainly more for the GPU to do, the numbers under a CPU limited configuration (800x600 with lower quality settings) we see a very low minimum framerate and a much lower average when compared to software physics.

    The drop in performance is much much less signficant when we look at a GPU limited configuration -- if all those object were bottlenecking on the graphics card, then giving them high quality textures and rendering them at a much higher resolution would show a bigger impact on performance.

    Tie that in with the fact that both the CPU and GPU limited configurations turn out the same minimum framerate and we really can conclude that the bottleneck is somewhere other than the GPU.

    It becomes more difficult to determin whether the bottleneck is at the CPU (game/driver/api overhead) or the PPU (pci bus/object generation/actual physics).

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