PhysX for ATI

Discussion in 'Videocards - AMD Radeon Drivers Section' started by AdmiralJanovsky, Apr 29, 2012.

  1. thatguy91

    thatguy91 Guest

    ATIStreamSDK :)

    OpenCL makes more sense in the long term than Cuda/Physx, but is much less developed. Same goes for Directcompute (Microsoft). Nvida, AMD, Intel etc all support OpenCL and Directcompute.
     
  2. Valagard

    Valagard Guest

    OpenCL is damn well developed, its faster then Cuda by around 15%

    But the downside is that Nvidia openly sponsers/pays developers to use Cuda, and companies are more likely to write software only for what they are getting paid for
     
  3. kn00tcn

    kn00tcn Ancient Guru

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    AO can be done by anyone on any platform, it's just a post process that calculates things based on the depth buffer, doesnt require 'hardware features' or anything, it's not like tesselation

    in fact check this out, AO in DOS on the cpu at 256 BYTES http://www.pouet.net/prod.php?which=53816

    which means... if the game doesnt have such a feature, nvidia has to always know the depth buffer value & inject some AO onto the image (bit of work that the amd team probably doesnt have the man power to set aside)

    unless there's a simpler way... with injectors, didnt ENB or ICE add AO to GTA4?
     
  4. sykozis

    sykozis Ancient Guru

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    Figured it was a typo, but wanted to make sure people have the right info.

    Older PhysX is limited to a single CPU core as it's bound by the restrictions placed on the x87 instruction set by Intel....which only allows for a single thread using x87 instructions to run at a time.

    x87 was actually moved to "legacy support" prior to Ageia coming into existance. They chose to use x87 for PhysX to give their PPU an advantage due to having the intent of selling PhysX after it was established. nVidia actually had no part in gimping PhysX when run on CPU....that was done by Ageia. nVidia was just in no hurry to correct the situation.
     

  5. kn00tcn

    kn00tcn Ancient Guru

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    just cuz something uses physx doesnt mean it's designed for gpu physx with a ton of particles, that's only a (relatively) small amount of games

    most physx usage in games is on the cpu for both nv & ati, identical to the console version of such a game (just like havok, etc)
     
  6. snaipo

    snaipo Guest

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    my cfg: 2500k/6970 12.4whql and i have 20-60fps in fight against boss-spider. gpu usage 99%. its not physx
     
  7. Valagard

    Valagard Guest

    I remember running PhysX tests on my Phenom, PHENOM, not Phenom II, using a Phenom and having it max out all 4 cores, and it was physx 1-2

    PhysX has always been able to multi-thread, its just older versions were limited by the amount of logical cores, newer versions 3.0 and up can make unlimited threads

    And that's lawyer double talk "They were in no hurry to to correct the situation" my ass, they never intended to fix it, they knew this was an issue -YEARS- ago, its only when they were caught fudging the results did they actually give a damn and fix it
     
    Last edited by a moderator: May 1, 2012
  8. Valagard

    Valagard Guest

    False, versions of PhysX on computers is not the same as PhysX on consoles, which is actually written for multi-threading like 3.0+ PhysX CPU for PC's

    That's where the huge scandal came from, some tech site decompiled and monitored the physx code, and versions older then 3.0 for PC/Mac would only run as many threads as you had logical cores. This would absolutely cripple it.

    The tech site then went into physx on Consoles (PS3/360) and found out that they freely run physx on the CPU, not GPU like nvidia said. That and the CPU was having no problems running the high levels of PhysX which was crippling games in the PC versions running the same amount of effects

    Further picking apart physx they found out why, it was using x87 code, it was limited by as many threads as logical cores, it capped itself on memory use etc etc etc. The whole thing blew up in Nvidia's face

    Nvidia said "We are not purposely crippling PhysX" and then two months later Physx 3.0 launched, and GPU advantage of PhysX vanished entirely, a four core Phenom II can run PhysX 2-3x as fast as a GTX 580 now

    And for those of you saying Nvidia wasn't purposely crippling physx on CPU, try to explain why Batman Arkham City, which uses the newest versions of Unreal 3.5+ engine, got shackled with a older outdated version of Physx? Several developers have already admitted they were forced to use the older PhysX at Nvidia's demand since they were sponsering the game, if they weren't trying to push PhysX GPU to try and sell videocards, why didn't they allow Rocksteady to use the newest versions of PhysX?


    @Snaipo: Binary Domain uses PhysX, its just written into the game code itself
     
    Last edited by a moderator: May 1, 2012
  9. TwL

    TwL Ancient Guru

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    This is absolutely incorrect information by all means.

    Check your facts.


    and this is heh, so far from truth you have no idea it seems what you are even talking about. As for your information Batman Arkham City was released on a physX platform which as of TODAY haven't yet been implemented on publicly released PhysX which has an physx block reset and has to separately registered as new physx engine(2.8.4.1) to your machine registry to be able to be hacked.
     
    Last edited: May 1, 2012
  10. Spets

    Spets Guest

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    When did Nv say consoles are running GPU PhysX?
    What console game runs "high" PhysX compared to PC? As far as I know they all run on low, which is easily supported on cpu's with the lack of particles.

    This isn't a surprise, they're using Ageia's original code, PhysX 3.x is a rebuild.

    GPU advantage hasn't vanished, and there's a huge difference in the amount of particles a 580 can handle compared a PhenomII, I'd like to see the review on this too.

    This has me interested, I thought certain modules of PhysX 3.x still need a lot of work to run properly, don't think Apex was working on v3 until the more recent months. Don't think it's exactly ready to be in games.
    Can you link me to the article?
     

  11. Redemption80

    Redemption80 Guest

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    Which “tech site” ran that article, as absolutely none of that is true, and I’m surprised you were gullible to believe it, as from a logical point of view it makes no sense.

    It’s not they could have been mistaken either, they must of went out their way to just lie, and just let the anti Nvidia propaganda machine do the rest for them.

    What console games did this site find that had all the PC GPU PhysX effects, but ran them freely on the CPU.

    Batman AC uses older versions of PhysX as 3.0 wasn’t out when they started the game, not because Nvidia forced them to use an older version.
    What many AMD users don’t know is that, 2.8.x isn’t optimised for the GPU either, so it wouldn’t make any sense to force dev’s to use the older one when 3.0 is much more optimised for GPU use, and would of made Nvidia GPU’s look better.
     
  12. teleguy

    teleguy Maha Guru

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    Really?

     
  13. Sr7

    Sr7 Master Guru

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    Actually no he's absolutely correct. NVIDIA has stated exactly what he said in multiple interviews. There was no automagic CPU threading with PhysX versions 2.8 and prior but devs could thread it themselves.

    Also after all the x87 complaints, aomeone did a test and confirmed it had negligible effects on perf vs x86. Just because of one article a bunch of people jumped to conclusions.
     
  14. XBEAST

    XBEAST Ancient Guru

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    More http://www.pcgameshardware.com/aid,...irectX-11-Tessellation-GPU-Physx-und-Co/News/

     
  15. snaipo

    snaipo Guest

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    - i can run game without installed physx
    - i have huge drop fps when gpu usage 99%. afaik physx uses cpu, not gpu.
    so, no physx in binary domain. bad optimisation of ati drivers
     

  16. kn00tcn

    kn00tcn Ancient Guru

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    :vader:

    -what i should have said by 'identical' was 'lightweight' cpu based, so for example, (excluding the gpu physx games) UE3 has always been physx since 2006, it's not crippled or too slow on non nv cards since it runs on the cpu for everyone+consoles

    -some engines just need an adjustment for ati (nfs shift 1 on launch! lost planet 2 currently is quite slower), slowdowns arent always caused by too much physics

    -the x87 stuff is curious, since i remember when skyrim came out, someone did some basic recompile to x86 & the minimum fps went way up

    -does anyone have railworks+nvidia card?
     
  17. Valagard

    Valagard Guest

    The skyrim one was the guy changing the lighting compiler from x86 to SSE2, which gave a huge boost, and he also enabled large block addressing, which further sped things up. Bethdesa put both changes into official skyrim patches and fixed these issues later on.
     
  18. Zareph

    Zareph Ancient Guru

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    ^ This exactly. Couldn't have put it better myself :)
     
  19. kn00tcn

    kn00tcn Ancient Guru

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    so if (older) physx is the same, would there be a chance of boosting specific (older) physx on cpu games?
     
  20. sykozis

    sykozis Ancient Guru

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    So, being written for the x87 instruction set, which is a single-threaded instruction set itself....how exactly is PhysX multi-threaded? Or is Intel lying???
     

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