Thoughts on PhysX

maxxfurygts · Post by **maxxfurygts** » 31 Aug 2008, 19:39

Hey guys, I'm looking for your thoughts on PhysX - not asking you for advice on whether I should invest in it because I already have a GTX280 but for your experiences with it. So far for me it's been something I'd rather have disabled in my games:

- it's a nice integration into CUDA but the effects run really slow in UT3 and generally drag down my framerate from the usual 60 to below 30... that Lighthouse map is especially bad, it looks like the bricks fall down and settle in slow motion!

- I've read and heard that Gears of War can use PhysX, but I have no idea whether the effects are on or off when I'm playing the game as there's no option like in UT3 to turn on Hardware Physics processing. Upon inspection of explosion effects in the game I can't discern any difference between accelerated and non-accelerated GoW.

- I haven't had time to try Splinter Cell Double Agent with PhysX but as far as I know there's no in-game option to enable PhysX either. Argh!

All in all I wish Intel had done something substantial with Havok.

Mesh · Post by **Mesh** » 31 Aug 2008, 21:57

I tried that 'physx pack' or whatever, and besides causing hard lockups requiring me to hold the power button to force a power down, it ain't worth scrap.

Could be the drivers themselves that are very beta buggy though, even non-physx things crash while 'gpu physics' is enabled.

Post by **Abram** » 01 Sep 2008, 00:01

My experience has been poor, but i blame it on the seperate hardware that Ageia had the balls to release. About $400 for slightly better visuals and a couple physics tricks, and then the usual lousy drivers, performance, and crashing that comes with new hardware types. Luckily i got my money back so it was a learning experience.

But now that the manufacturers are finally slaping physics CPUs onto the video card pcb and with Nvidia enabling it on regular video cards my hopes are a bit higher.

I just hope this thing becomes practical and wide-spread enough to justify developers properly including support in games and maybe we'll finally see something worthwhile in the near future.

So far it's another good-idea-but-poor-execution thing.

Oh and since i have a single 8800 right now i haven't tried converting it. That will wait for my next upgrade. For once i kind of regret buying a single PCI-E slot mobo.

skeeder · Post by **skeeder** » 01 Sep 2008, 03:34

agreed. I played that Crossover game...the Agiea only release. It was fun, but from what I was told even with the card it ran like a dog.

Honestly I'm not sold on the idea AT ALL. In my experience while physX's do take up some CPU, I think with the PhysX company gone and in the hands of NVIDIA they might turn it into something useful.

[email protected] · Post by **[email protected]** » 01 Sep 2008, 03:43

Unreal Tournament 3
Well as far as UT3 goes I am quite unimpressed, Tornado had near no destructible elements, and looking at the tornado dropped my FPS, Lighthouse had very few destructible elements, Heat Ray had no destructible elements that I could find and had hail spawning 12 inches off the ground looked really cool when you shot those gravity ball thingies tho.

I also saw several physics related bugs namely objects sliding very slowly not reacting to nearby explosions or direct gunshots. I even saw some glass free falling in slow mo (under normal gravity) also the destructible items behaved quite unpredictably and inconsistently, you shoot section c and section c, b and a are destroyed leaving d and e intact.

When you destroy a glass screen it is replaced with a cracked texture that appeared to be premade instead of generated and new glass fragments spawned from nowhere leaving the original screen completely intact but cracked.

The only things I saw that something like the source engine wouldn't be able to do were completely visual not affecting gameplay in the least.

Warmonger: Downtown Destruction
I also tried Warmonger and was rather impressed compared to UT3 the cloth simulations were plentiful, looked great and accurate even when ripped. Ripped cloth needs some polishing as it currently looks heavily polygonated, But this could be solved with some type of dynamic transparencies applied to the textures along the ripped edges. These cloths have a minor affect on gameplay.

The environments while not completely destructible were more-so than UT3. Altho when you blow a brick wall in Warmonger it graks off in large chunks while in UT3 it goes into individual bricks, but this appears to be purely cosmetic.

Warmonger has lots of papers flying through it which looked nice, also the floating blowing embers in one of the levels (they look quite similar to the hale in Heat Ray on UT3 but much lighter and affected by the wind. I liked it lots.

In both games I saw lots of collisions of non gameplay objects and in the case of UT3 gameplay objects as well.

Demos
They looked Really cool and impressive but lac creativity and artistic value.

Uhh on second thought maybe I should take another look at them.

CellFactor: Revolution
Does not support Nvidia Hardware.

Thoughts
I hope one day we will see games with fully destructible environments, with real looking simulations of walls being broken instead of being clearly, partially scripted (Warmonger) or Unpredictable UT3

I can imagine a simple touch to a game like police tape blowing in the wind will look great and be quite easy to implement. Also effects like snow, rain, hale and water flowing have great potential.

If anyone has any free mods or games that support PhysX acceleration for me to try or inexpensive games <$30 to recommend then I am interested and will gladly add them to this review.[/b]

maxxfurygts · Post by **maxxfurygts** » 01 Sep 2008, 04:04

Yeah I noticed alot of slow-mo stuff in UT3 too (while everything else is going on in real time) as well as the lack of polish with the glass breaking. I'll have to check out that Warmonger game you mentioned though, seems like it's a little more optimized than what these disillusioned eyes are used to.

[email protected] · Post by **[email protected]** » 01 Sep 2008, 04:12

Don't get your hopes up too high, google force within, you should be able to find your way from there, the Nvidia download manager is leet.

Post by **Abram** » 01 Sep 2008, 06:03

Off topic but oooo when did my staus get to 'Insider'? I feel so nerdy.

I guess i may as well summzrize my feelings on physx again.

Past and now = boo.

Potential future = Yay!

Realisticly = may be redundant in a couple years.

Post by **scavvenjahh** » 02 Sep 2008, 10:47

Ow... A PhysX thread. Yum yum :P
Prepare for a quotefest...

- it's a nice integration into CUDA but the effects run really slow in UT3 and generally drag down my framerate from the usual 60 to below 30... that Lighthouse map is especially bad, it looks like the bricks fall down and settle in slow motion!
>>Lots of debris = less fps than on vanilla maps... but "slomo" with a card like yours ?? Did you try the latest drivers ?

- I've read and heard that Gears of War can use PhysX, but I have no idea whether the effects are on or off when I'm playing the game as there's no option like in UT3 to turn on Hardware Physics processing. Upon inspection of explosion effects in the game I can't discern any difference between accelerated and non-accelerated GoW.
>>And that's where people get confused about PhysX : you can't always accelerate it using a GeForce or Ageia card ! It's basically only a part of a game's engine dedicated to physics (gravity and such). Lots of games use it - but very few feature hardware PhysX support or advanced Physx effects... GoW, like all UE3-based games, uses PhysX - but unlike UT3, it doesn't support hardware acceleration of PhysX afaik.

- I haven't had time to try Splinter Cell Double Agent with PhysX but as far as I know there's no in-game option to enable PhysX either. Argh!
>>Same here. I think you don't even need to install the PhysX drivers except for multiplayer mode (not sure). No hardware support anyway.

All in all I wish Intel had done something substantial with Havok.
>>and I wish nvidia will do sth substantial with PhysX ! :lol: (Still very few titles at the moment...)

agreed. I played that Crossover game...the Agiea only release. It was fun, but from what I was told even with the card it ran like a dog.
>> :?: What is that game ??

Unreal Tournament 3
Well as far as UT3 goes I am quite unimpressed, Tornado had near no destructible elements, ... Lighthouse had very few destructible elements, Heat Ray had no destructible elements that I could find ...
>> :shock: Were you playing with your eyes closed ? Or in Spectator mode ?? :lol:

-Tornado : all concrete walls ! windows ! red steam pipes ! energy balls/locks !
-Lighthouse : barrels ! passages through bricks walls, concrete floors and ceilings ! windows ! wood planks !
-Heat Ray PhysX : barricades ! neon signs (yeah, even that dragon over there) ! wooden platforms ! gas canisters !

Thoughts
I hope one day we will see games with fully destructible environments, with real looking simulations of walls being broken instead of being clearly, partially scripted (Warmonger) or Unpredictable UT3
>>Unpredictable ? Play a couple rounds and you know exactly which parts of a brick wall will break on Lighthouse. C'mon, advanced PhysX deserves more than a 2-minute ride on each map ! And I'm not saying so just because I'm a declared 'worshipper' of that stuff :mrgreen:

I can imagine a simple touch to a game like police tape blowing in the wind will look great and be quite easy to implement. Also effects like snow, rain, hale and water flowing have great potential.
>>Realistic cloth movement (i.e not just an animation loop) already exists in lots of games and doesn't require PhysX's capabilities. It's tearable cloth I'd like to see everywhere !
You should try Switchball (no hw acceleration required, since the game is alas capped at 30 fps...), it has a clever (though sadly underused) way of using this feature : cloth platforms will sustain the weight of a marble ball, but will break under a metal ball - thus leading to "death"... or hidden alternate routes ! :)

"Climatic debris", wind effects and water are interesting too, but I'm not sure PhysX is really appropriate for these. As non-gameplay elements, they'd need to look good before all, and in phase with each game's aesthetics/mood/atmosphere - and PhysX tends to look so like... PhysX. :?

I certainly hope we'll have a new Cellfactor that's compatible with PhysX on GeForce soon. Though unrefined/beta FPSs, the previous Cellfactor titles were a real showcase of what a heavy dose of PhysX can bring to the table - new gameplay possibilities and pure insane fun !

skeeder · Post by **skeeder** » 02 Sep 2008, 23:57

btw: it was cellfactor.

Just so you know.

maxxfurygts · Post by **maxxfurygts** » 03 Sep 2008, 01:49

>>Lots of debris = less fps than on vanilla maps... but "slomo" with a card like yours ?? Did you try the latest drivers ?

Yeah, I have the latest 177.whatever drivers direct from the NVIDIA CUDA mini page. Perhaps it's a matter of running the graphics and physics calculations all on one GPU core? I play everything at 1680x1050 resolution, so that might be a little taxing when I start throwing exploding brick walls into the mix. Not that it terribly matters because I don't really like the three maps are designed anyway, haha. The new Facing Worlds map, however, is quite a delight.

>>And that's where people get confused about PhysX : you can't always accelerate it using a GeForce or Ageia card ! It's basically only a part of a game's engine dedicated to physics (gravity and such). Lots of games use it - but very few feature hardware PhysX support or advanced Physx effects... GoW, like all UE3-based games, uses PhysX - but unlike UT3, it doesn't support hardware acceleration of PhysX afaik.

Right. I hadn't thought of that, even though I knew there was software and hardware acceleration. Thanks for the reminder!

I'll try out Switchball too, I'm a big fan of those fun casual games. Off-topic, but ever try out Grid Wars (1 or 2, but I've only tried 2)? It's the freeware ripoff of Geometry Wars...

maxxfurygts · Post by **maxxfurygts** » 03 Sep 2008, 02:12

Don't get your hopes up too high, google force within, you should be able to find your way from there, the Nvidia download manager is leet.

Hm. When did you get the power pack Edward? I keep getting a message stating "The server returned an error. Would you like to retry?" when the download initiates. I'll try later I suppose.

[edit]Nevermind, I saw the link for downloading the files individually.

Mergatroid · Post by **Mergatroid** » 03 Sep 2008, 16:32

My opinion is that they've turned their video cards into sales gimmicks. I don't believe for one second that nVidia structured their architecture to fully utilize the current 3d api's while, at the same time, allowed for concurrent processing for the Physx api.

I would place my money on a conversation like this:

nVidia exec: "Hey, Ageia looks like a buyable company, any way we can leverage that?"
Corporate yes-men: "Absolutely, we have processors on our cards, we can use those to run the api. Oooooo! Oooooo! We can even give it an acronym!"
ne: "That's a good idea, I'm glad I thought of it. Call it CUDA, you know, like barracuda, 'cause I like that. Make it an acronym or something. Oh, and buy Ageia."
cy: "You got it, Boss!"

cy: "Here, make the 8x, 9x and new 200 line of cards do this." Hands an engineer a 1 page document explaining more about the acronym than any sort of requirements or even business spec.
nVidia engineer: "Um, this really isn't possible, you see..." He goes on for about 10 minutes explaining all the very good reasons why this is a bad, bad idea. The cy hears "blah, blah, tech-stuff, blah, blah, hope-it's-sunny-for-golf, blah".
cy: "Whatever. Make it happen or your fired."
ne: "Sigh. Ok."

The cards were not made for this. The simple proof is that they almost all have single core processors. Ageia cards have their own processors for a reason, and 1 processor to do the work of 2 will cut performance by about 66% (not half. There's quite a bit of overhead involved in concurrent processing).

Sorry for the extra bile and ire in this post. I have a huge problem with companies that lie to their customers to get them to buy their products, and I see this as exactly that. I also have a huge problem with nVidia now. If you would like to know more about that, I made a blog post here a little while ago that you can read.

I know this is the way most corporations work. I still don't like it.

Frag Maniac · Post by **Frag Maniac** » 07 Sep 2008, 08:30

[quote]Perhaps it's a matter of running the graphics and physics calculations all on one GPU core?.

YA THINK? No seriously, that's exactly what came to mind when I read your comments. With games as resource hungry as they are, many now having lots of destructible objects, I feel you either need a dedicated processor on the video card to run PhysX or run it via the CPU, like physics have been traditionally, esp if it's a multi core CPU.

Back when there were rumors (false of course) of the 8800 having a dedicated physics processor, I assumed from what I'd read about Nvidia's incorporation of virtual physics processing on those GPUs via software laying that their next step would be a dedicated physics processor on board. It appears the route they've gone though will result in your top shelf card suddenly performing like a mid-range one should you want to employ PhysX.

Post by **scavvenjahh** » 08 Sep 2008, 10:22

Nice broken quote :P

Sigh. Here we go again.
You can't just have a "PhysX processor" on a graphics card like that - the good old Ageia P100 card has 36 cores... That's why shader programming and CUDA are such a clever way to deal with the problem. That's also why it doesn't make sense to think "a multicore CPU" can handle advanced PhysX effects along with all the rest. It's not only computational power we need, it's friggin' parallelism. We'll see what 18-core Nehalems and whatnot can do for PhysX, the engine itself probably needs optimizing too, but from here on we're entering Speculationland...

FYI using your main graphics card OR a PPU to do the PhysX will give similar framerates - it even seems PhysX on GeForce definitely beats the PPU with newer drivers !
http://www.firingsquad.com/hardware/physx_performance_update/

The problem is advanced PhysX always taxes framerates to begin with - but don't forget the UT3 maps like all "advanced PhysX" features are still tech demos, and as such they're pretty unrefined and resource-hungry. PhysX can probably get better than that... the problem is, when will it actually start to happen ? :?

Post by **Paradigm Shifter** » 08 Sep 2008, 12:08

PhysX can probably get better than that... the problem is, when will it actually start to happen ?

When there is something unified (probably in DirectX) that every system can call to, whether it has an Intel CPU, and AMD one, ATi VPU or nVidia GPU. ;)

Mergatroid · Post by **Mergatroid** » 09 Sep 2008, 16:29

stuff

I stand corrected in my knowledge of the technology.

My original point is still valid, however. The cards were not made for this and I still think it's a gimmick.

Or maybe I'm just bitter. :?

Post by **scavvenjahh** » 09 Sep 2008, 17:15

OR my english vocabulary is somewhat limited :oops:

Some nvidia official stated in an interview that PhysX on GPU is a bit like AA : "using it may have a performance cost, but it's still a nice feature, right ?" Given the few titles we can test at the moment, all in all, I tend to agree. Plus I have a killer gaming rig and have very playable framerates no matter what on all UT3 PhysX maps. (So yes, be bitter!) :lol:

The problem with PhysX is you can only hate it as long as you didn't actually see it in action - I pity the ones who never saw an Ageia card at work managing the insane amount of debris in the old, broken, unoptimized and then again kickass and promising Cellfactor games !

I know I sound like a fanboy, and again, blame my english. I just wish to explain what I know about this ever-underrated, now-controversial technology. As for picking a graphics card because it supports PhysX or DX10.1 or not, it's simply foolish at the moment.

maxxfurygts · Post by **maxxfurygts** » 10 Sep 2008, 01:58

YA THINK? No seriously, that's exactly what came to mind when I read your comments. With games as resource hungry as they are, many now having lots of destructible objects, I feel you either need a dedicated processor on the video card to run PhysX or run it via the CPU, like physics have been traditionally, esp if it's a multi core CPU.

Back when there were rumors (false of course) of the 8800 having a dedicated physics processor, I assumed from what I'd read about Nvidia's incorporation of virtual physics processing on those GPUs via software laying that their next step would be a dedicated physics processor on board. It appears the route they've gone though will result in your top shelf card suddenly performing like a mid-range one should you want to employ PhysX.

That's what I initially thought Frag Maniac, but then I remembered that that's really only true of last-generation technology (althought I wouldn't mind having a second GTX in my case). I think it's important to remember that the 8 + 9 + GT200 cards all have significant multithread processing capabilities, and with 240 stream processors it's inexcusable that I can't run Heatray_PhysX beyond 30 FPS on the most scalable game engine next to Source. It's all very interesting really, if not confusing. I've seen all the Tom's Hardware and [H]ardOCP and whatever-other-site-out-there benchmarks showing GeForce-based PhysX beating out the original PCI-based PPU, so it seems a little crazy that Epic (and other PhysX partners) and nVIDIA wouldn't work a *little* closer on integration into the game, as opposed to blaming the technology, especially when you see gameplay videos for, say, Cellfactor. Understandably, CUDA's real usefulness lies in computing - like with the simulations for protein structure synthesis at Stanford or whichever university.

That's just my theory: that it's a combination of a need to properly implement PhysX and immaturity of the technology, rather than a simple matter of not having enough video cards stuffed into your rig.

Post by **Tamlin** » 13 Sep 2008, 09:51

OR my english vocabulary is somewhat limited :oops:

Some nvidia official stated in an interview that PhysX on GPU is a bit like AA : "using it may have a performance cost, but it's still a nice feature, right ?" Given the few titles we can test at the moment, all in all, I tend to agree. Plus I have a killer gaming rig and have very playable framerates no matter what on all UT3 PhysX maps. (So yes, be bitter!) :lol:

More titles will come. :) Age of Conan is getting PhysX as well:
http://www.bit-tech.net/news/2008/08/28/age-of-conan-directx-10-content-looks-stunning/1

All new features that can gives us more joy when gaming is welcome. :D

It will be interesting to see what happens with the physics in the coming year.

Intel have its Havoc, which support most games at the moment. Their new processor series might gives us great physics without sacrificing FPS, AA and AF.

DirectX 11 brings physics to every user.

Nvidia's PhysX can be used on more then Nvidia cards:
http://www.tgdaily.com/content/view/38137/135/

It all depends what directions they are chosing to take.

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