PhysX support

[cd_toaster]

yo i search the forums for the last 4 months and find anything so....
i recently went back to the PhysX website and they have videos and stuff up there now and a list of companies supporting PhysX along with Unreal Engine 3 and its had lots of blabla about they have been working with the physx SDK. i also checked out the website for Unreal Engine 3 and looked in accounced titles for Unreal Engine 3 and found Duke Nukem Forever http://forums.3drealms.com/ubbthreads/images/graemlins/redface.gif i thoguht you guys were using a different engine. anyway does that mean Duke Nukem Forever will support the PhysX card?

here are some links:
http://www.ageia.com/physxInAction/unreal.html
http://www.unrealtechnology.com/flash/powered/announced.shtml (flash site)

[ADM]

That page isn't showing the list of games/developers using the Unreal Engine 3 technology, it's showing who's using the Unreal Technology in general.

If you go by your theory then Tribes: Vengeance and Pariah would have had to be using Unreal Engine 3.

DNF is using Unreal Engine 2 code (and if I'm not mistaken some UE1 code as well) and it's own rendering engine. I'm also sure that there would be some UE3 code in DNF for some things but no they didn't switch engines, their engine has been stable for the past year or so.

As for PhysX, yes theres a possibility that DNF is now using it as they were using Meqon but Meqon has been bought out by Ageia. Not too sure if 3DR still continued using the Meqon SDK or if it was still being developed by Ageia.

[cd_toaster]

sorry about posting a question about feature X http://forums.3drealms.com/ubbthreads/images/graemlins/doh.gif
i didnt think it wasnt allowed but i looked in rules again and saw it wasnt but it didnt let me delete it http://forums.3drealms.com/ubbthreads/images/graemlins/frown.gif

[hell-angel]

I think this is more of a "Should DNF use the Physx engine" But that has been discussed a lot here allready. http://forums.3drealms.com/ubbthreads/images/graemlins/smile.gif Search is you friend. http://forums.3drealms.com/ubbthreads/images/graemlins/wink.gif

still, it would be nice for Ageia as well as DNF if they used it. http://forums.3drealms.com/ubbthreads/images/graemlins/wink.gif http://forums.3drealms.com/ubbthreads/images/graemlins/grin.gif

[Kalki]

George Broussard said:

“It's going to be a long long time before enough people have PPU's so that you can count on them being there, without having to put in low quality and high quality physics.

The problem is that you can't go nuts with physics when 1% of your market has a PPU.

Even with video cards, there is a fine line and people always opt to dumb the visuals down so they run on lower end cards. This always affects how high you can do on the high end, because you still have to scale to some reasonable low end.

We are just now starting to see games that will push high end visuals and start to abandon older cards.

But I think it's going to be a long time before you can do that for a physics card. So in the mean time you will have situations where people just do more rubble or debris, when there is a PPU available.

And I still don't see people spending $200 for a PPU like they do for a GPU. I think it will be a pretty small market, comparatively. But I hope it's the future and the PPU's move onto video cards or motherboards. That's what needs to happen for it to get widespread.” link (http://forums.3drealms.com/ubbthreads/showflat.php?Cat=&Board=dnf&Number=856015&Searchpage=1&Main=855617&Search=true#Post856015)




George Broussard said:

“You cannot fully support the Ageia PPU, as not enough people have it, or will have it, any time soon. Every developer I know is doing "normal" physics that run in software, but has some extra fluff stuff if there is a PPU present.

I just don't think it will be that impacting, short term. In 3-4 years, maybe. When it gets in a console unit, or on a motherboard, sure. I just do not believe that many people will pay $200 for a PPU, and that means that support will be miminal at first, and only grow as card penetration does. I would expect that penetration to be slow unless there are significant hardware deals.” link (http://forums.3drealms.com/ubbthreads/showflat.php?Cat=&Board=dnf&Number=938984&Searchpage=1&Main=937405&Search=true#Post938984)

[cd_toaster]

oh i searched for ageia wierd :S. yea i thought there may be a problem with that. producers wont make games for it unless people buy it but people wont buy it unless there are games for it. i think the price is a bit steep, they are a bit stupid. they should put it out on the market realt cheap first with a game that supports it so lots of people buy it and show their friends etc

[GambitMR]

well I believe the first game using AGEIA is Bet on Soldier ... which I strangely liked ( especially the fact that you can tear down the enemies amor bit by bit ...thx AGEIA) ... but sadly the developer decided to not release any patches anymore and so you can't complete the Singleplayer .. and MP is fuxxored from what I've heard.

anyway .. cd_toaster is right ... need proof ? windows.

[skumlex]

Well, we had the same problem with the voodoo1 cards, noone wanted to buy them because there were only a few games supporting them, and look where we are now. The move to 3D in computer games ows alot to 3DFX. I belive a hardware physics crad can change the games scene in similar ways. At least I hope so, because the prospects are so enormous that I would wish the card and games were here NOW. I WILL be buying a card when they come out.
By the way we have a different situation now than with the voodoo1 because we will have mod teams who are more likely to utilize the physics card much more because they wont have millions of dollars riding on a game they have to sell. So I think Ageia should bet on the mod community.

[hell-angel]

We can only hope that it will change gaming in a positive aspect. But that all depends on how expensive they are.

[BabyFace]

I dunno... expensive graphics card + expensive physix card = in-PC-game console, but abouth three times as expensive? There's a point where I'd really ask myself if I want to have to buy all that additional hardware to get a decent gaming system.

I think for hardware physics to become really popular two things should happen:

- Definition of a standard API (like OpenGL or Direct3D for graphics)
- Inclusion of physics chips on the graphics card

Especially the first one is important. I'll sure as hell not buy a card as long as there isn't any kind of standard (be it just a de-facto one) to which a majority of the game producers agree.

[DudeMiester]

As multicore CPUs scale into non-heterogenius CPUs like CELL, items like the PPU will become redundant. I mean all the PPU is really, is a CELL minus the PowerPC core. Of course, it'll be 4 or 5 years until then, but nevertheless, the PPU is a doomed product. Unless, of course, they market it as a general purpose co-processor and make the API to match. Then at the very least, scientific people might still buy it.

[Malgon]

DudeMiester, you always have a way of putting things like this into perspective. You're most probably right. http://forums.3drealms.com/ubbthreads/images/graemlins/wink.gif http://forums.3drealms.com/ubbthreads/images/graemlins/grin.gif

I guess we'll see how it'll pan out anyway. http://forums.3drealms.com/ubbthreads/images/graemlins/smile.gif

[Codey]

It's easy really, 3DR should buy 50%+ share in the company and therefore have access to the cards at manufacturing cost, package the card with the game and violla!

[skumlex]

I have to disagree with you Dudemeister for several reasons:

First of all, we are only now seeing dualcore cpus in pcs, and the extra cost for the second core is not much lower than what the Physx card will cost. (A Athlon X2 3800+ which is according to Anandtech "basically two Athlon 64 3200+" costs 364$ and the Athlon 64 3200+ costs 173$) The timeframe before the general public will own even a dualcore set up let alone a multicore setup would be at least 4-5 years as you say, but the Physx chip will be out in jan-feb next year. So developers can take advantage if the chip now!

Secondly as stated in an article on the physx chip (http://www.anandtech.com/cpuchipsets/showdoc.aspx?i=2376) the multicore cpu is not very suitable for computing physics data: "So, here’s the real question. Why won’t Intel’s vision of multi and many-core processors be good enough to handle what a discrete PPU could handle?

Of course more parallel processing power will help no matter how it comes. But the deeper issue is data movement. The example AGEIA gave us to think about was a huge pile of bricks; when you push down on one brick near the top, forces are transferred to all other bricks in the stack. This may not be difficult on the scale to hundreds, but how about 30000 objects in a stack? How about keeping track of that while handling deformable (soft body) objects, fluids, and all collision detection in the scene?

The way all this needs to be handled is not simply with lots of parallel independent floating point power, but with lots of parallel floating point power connected by huge bandwidth. The fact that some initial Intel dual core chips will have to go off chip and back on to communicate, not as much performance is gained as possible. Certainly more parallelism is better no matter what, but it’s the high bandwidth that clenches the deal."

The situation can be compared to that of graphics. The reason we have graphics cards is because the cpu can NOT handle a lot of parallel computing. But a graphics chip specifically designed for the task and running at a mere 430mhz (The GeForce 7800GTX) can produce very beautiful graphics.

Another argument against dualcore cpus handling physics is the fact that Havok is competing against Ageia, but they claim that the graphics chip isn't under full stress all the time and since the graphics chip is good at parallel computing they intend to use the unused power for physics, but as mentioned is in this article (http://www.anandtech.com/video/showdoc.aspx?i=2585) they predict that a SLI or Crossfire setup is best suited for the task, which means extra cash for that second graphics card, and maybe a new motherboard.

So after all this babble what I am trying to say is: You don't get nothing for free not even physics. So sooner or later you will have to pay to have 30.000 plus objects moving at once, and soft body dynamics, and fluids and cloth simulation.

[DudeMiester]

There's a reason they also call the CELL, the Broadband Engine. It's because there are 128GB/s of bandwidth between the processing elements. More then enough for any physics simulation.

[neuromancer]

I think the PPU vs GPU comparison was set in a wrong context. We need GPUs mainly because the required bandwidth can not be handled by the CPU. Secondly, we need them to do complex per-pixel calculations. I can play most of the new games in my Ti4200 in low quality because it can handle the geometry. But when I am going to high quality its limited bandwidth converts the game into a slideshow. A PPU's objective is to do the physics maths, a task less demanding in bandwidth, IMHO. So, as soon as the CPU is powerfull, a physics engine in the class of Meqon can be easily handled by the CPU. Besides, I prefer investing in a more powerfull CPU and utilize it in all the apps I run, than buing a physics card which will be used only in games. Who knows, maybe the next MMX/SSE/3DNow extensions are about physics.

[Kristian Joensen]

DudeMiester said:
There's a reason they also call the CELL, the Broadband Engine. It's because there are 128GB/s of bandwidth between the processing elements. More then enough for any physics simulation.



What are you talking about, I think you are confusin the CELL with the Revolutions CPU.

[DudeMiester]

Oh sorry I am mistaken, see:

http://pc.watch.impress.co.jp/docs/2005/0208/kaigai01l.gif

There is 768 bits/cycle or 96 bytes/cycle bandwidth, and at 3.2Ghz you have 286GB/s of bandwidth. Sorry my bad there. http://forums.3drealms.com/ubbthreads/images/graemlins/tongue.gif

[Kristian Joensen]

It was not the number I was talking about but The broadband thing I believe Broadband is the codename of Revolutions CPU not the CELL processor.

[FireFly]

Actually that's the Broadway.

[skumlex]

Dudemeister: The most important thing for physics calculation is not the bandwidth between the physx and the cpu since the physics data sent over the bus is relativly small, and therefore the pcibus is not a bottleneck. The real bandwidth consumption happens inside the chip. But looking at Ageias own schematics they put the physx processer rigth next to the CELL and teh XBOX360 POWERPC cpus so they probably also thinks those cpu's are powerfull enough, but there is only a slight problem: The mentioned cpus reside inside consoles, and I am a PC-man, and I want physics on my pc. Granted the CELL might be powerfull enough, but even dualcore for the PC still costs almost the same as two CPUs, and there is also another problem with multicore processors and thats is they require multithreaded programming which according to Gabe Newell from Valve is much more difficult. "If writing in-order code [in terms of difficulty] is a one and writing out-of-order code is a four, then writing multicore code is a 10." (http://www.next-gen.biz/index.php?option=com_content&task=view&id=510&Itemid=2)

Neromancer:
The GPU uses the most bandwidth on moving textures from memory (both system and graphics memory) to the GPU, as you note the bandwidth is high enough for polygon data, but the per pixel calculation can easily be compared to the physics caluclation since the amount of simultanious calculations are enormous. And the generel purpose CPU is not designed for this kind of work so I don't believe that an extension like 3DNow and so on will be enough. Especially when taking in to account that the hardware itself is a 125 million transistor chip built on TSMC’s 130nm process, and sports 128 MB DDR3 memory. So as you can see this is serious hardware.

To repeat myself, Physics WILL cost extra, be it on more cores, or on specialized hardware. And by the way the the discussion is irrellevant since the physics that Duke will use is not going to be nowhere near the visions that Ageia has with the Physx chip. To repeat the Words of George: Dont buy hardware now, wait till the game ships. (In 2020, where we will be able to play it on our mobilephones)

[baff]

I agree about the money, no pay no play. If you don't want the best, don't buy it.

There are no PPU's in consoles and comparing PPU's power to the power of console CPU's isn't a very impressive benchmark.
Despite what the hype says, you are right when you say if you want power you are going to have to pay for it.
NB consoles are all VERY cheap. A a single core Celeron 1.7 will outperform an Xbox CPU, for example, and can be bought for £20. For all it's "dual cores" it's just a cheap chip. In terms of consoles it's revolutionary but in terms of computational power it's rather primitive.

<font color="yellow">Unreal </font> will support Ageia in it's next incarnation, given the hundreds of games that are made using Unreal engine, I think we can take it as a given that Ageia is on it's way.

A lot of games developments are beginning to pay lip service to supporting Ageia. In the most cases I would have to say seeing is believing.
Unreal probably has the resources available to develop the code and show it off. They are always looking for new technologies to place them one jump ahead of the competition. It's a technology title. Now they have taken it onboard I fully expect to see it in all it's glory within a year.

The test for me will be to watch two ingame movies made on the same game one with Ageia, one without. If it's good I will buy it.

[DudeMiester]

skumlex said:
Dudemeister: The most important thing for physics calculation is not the bandwidth between the physx and the cpu since the physics data sent over the bus is relativly small, and therefore the pcibus is not a bottleneck. The real bandwidth consumption happens inside the chip. But looking at Ageias own schematics they put the physx processer rigth next to the CELL and teh XBOX360 POWERPC cpus so they probably also thinks those cpu's are powerfull enough, but there is only a slight problem: The mentioned cpus reside inside consoles, and I am a PC-man, and I want physics on my pc. Granted the CELL might be powerfull enough, but even dualcore for the PC still costs almost the same as two CPUs, and there is also another problem with multicore processors and thats is they require multithreaded programming which according to Gabe Newell from Valve is much more difficult. "If writing in-order code [in terms of difficulty] is a one and writing out-of-order code is a four, then writing multicore code is a 10." (http://www.next-gen.biz/index.php?option=com_content&task=view&id=510&Itemid=2)



First of all, Gabe Newell is an idiot. fyi, he doesn't actually program anything anymore, so how should he know. The fact is that out of order execution was created because it's EASIER to code for, so there's goes Gabe's credibility out the window. Also, I've coded multi-threaded software myself, and it's not that hard. You just have to understand how your program will operate, something any half-decent coder should know anyways.

Second of all, and maybe you're just tired or something, but when I'm talking about the CELL that bandwidth is inside the chip! If you look carefully at the image I sent, or if you actually knew anything about CELL, you would realise that.

I'm writing my own multi-threaded physics engine, so I understand how these things work.

[Micki!]

DudeMiester said:

I'm writing my own multi-threaded physics engine, so I understand how these things work.



Cool..! Are you going to share some news with us about this sooner..? http://forums.3drealms.com/ubbthreads/images/graemlins/smile.gif

[FireFly]

DudeMiester said:
First of all, Gabe Newell is an idiot. fyi, he doesn't actually program anything anymore, so how should he know. The fact is that out of order execution was created because it's EASIER to code for, so there's goes Gabe's credibility out the window.


He just mixed up out of order with in order. That's all.

[DudeMiester]

Micki! said:

DudeMiester said:

I'm writing my own multi-threaded physics engine, so I understand how these things work.



Cool..! Are you going to share some news with us about this sooner..? http://forums.3drealms.com/ubbthreads/images/graemlins/smile.gif



It's on hold for now, I'm doing some other stuff. However, the algorithm is there, and I've checked every angle. It will work, I have no doubt of that. Although, I don't know how many objects I will be able to simulate at once, but I'm aiming for 1000. You know, the most important part about collision detection is not actually detecting the collision, it's culling out all the invalid ones, lol. Either way, it's a lot of work and will take quite a while to complete.

[Micki!]

Sounds interresting...
Although, it might take some time, i'm seeing forward to any furture info about it... I always wanted to see what stuff your able to create... (since you couldn't help with our game project (Sig))

[skumlex]

Sure Gabe might be an idiot, and sure the Cell is awesome, but i it s still only in the PS3, and i wont buy any console soon. Cool that you are coding a multithreaded physics engine, but if it only runs on dualcore cpus, my argument still holds, that you will have to pay to play. And I would probably still shell out for that physx card than another core in my cpu. There is more to Novodex than colliding objects, they have cloth, hair and fluid simulation as well as soft body dynamics.

[skumlex]

Oh by the way Dudemeister I looked at the picture of the Cell processor you send, but the bandwidth you mention is between the cores. The bandwidth I am talking about is the amount of physics calculations that the physx is able to do.

Lets assume that a physicsengine is able to use all the cores in cell processor (lets just use the one in the PS3 since I have'nt heard of any other implementation yet) that means 7 cores. If they are to handle the same amount of objects as the physx this means each core has to calculate 30.000/7 objects. Your physics engine is aiming at 1000, and the current Havok engine which runs on normal cpus can handle around 100-150 objects (without hair, cloth and fluid simulation as well as soft body dynamics).

So each Cell core has to handle 4285 objects each and in a multicore multithreaded environment. The physx is ONE chip that can handle 30.000 objects on its own.

Havok does'nt believe in multicores either since they a betting on utilizing the unused powers of you graphics card.

[DudeMiester]

First of all the SPEs on the CELL are absolute beasts when it comes to FP operations, way more then any current CPU. For example, they can each decode an HD H.264 stream real-time, which an A64 3000 would seriously struggle with. Second, they don't all run entire simulations, they run parts of the simulation, so you can't compare it to current CPU or engine. Third, the current engines say 100 to 150, when including all the other processing the CPU must do! On the CELL, each SPE will be totally devoted to it's particular task. All in all, you can't compare numbers between the CELL/PPU and regular CPUs.

btw, GPUs have been heavily multi-core for a LONG time. Each pixel quad, vertex chader, ROP, etc... is it's own specialised core. There's an interview with an Nvidia guy that says exactly this. Therefore, Havok is supporting multi-cores anyways, lol. Nevertheless, they will in fact support multi-core CPUs, and I don't know where you got the idea that they weren't.

Finally, the PPU is heavily multi-core internally, I assure you of that. It's probably designed almost the same as the CELL, like I said. If you look at the backgroud of the company developing it, it makes sense. They specialise is high-bandwidth busses and fast and small processors for use in network appliances, but would also work perfectly for a PPU. Moreover, The company that made the PPU, bought out Ageia specifically because it's multi-threaded, since the PPU is heavily multi-core.

[Kristian Joensen]

I must me misunderstanding something, isn't it Ageia which is making the PPU ?

Also what IS PhysX ? The PPU ? An actualy physics card containing a PPU ? A physics API ? A Physics engine ? Where does Novodex fit in with all of this ?

[Gryph]

From what I understand Novodex is the SDK and PhysX is the processor and/or the entire technology.

[DudeMiester]

Sorry, I meant when Ageia bought out Novodex.

[skumlex]

Sorry Dudemeister you are wise in the ways of physics, I am but a humble misguided ignoramus.

But my argument still stands. The Cell is still only in the PS3, and I don't suscpect that Microsoft will code Windows for the Cell even if it were to be found i PC's some day. (And there only very few Game studios that port for Linux)

So for physics on the PC we have Havok and Ageia. If Havok can pull the same physics calculation out of a single core (or perhaps dualcore when they are commonplace in a few years) and a single graphics card, so I don't have to upgrade I will cry a little tear. But we will have to wait and see. Lets hope they can have a new version of their physics engine out by the time Ageia releases the Physx chip.

To clear all it all up: Ageia is the name of the company. Physx is the name of the Hardware chip they are making. Novodex is the name of the SDK.

[DudeMiester]

Well of course MS won't make Window's for CELL any time soon. Although they might eventually, if CELL really takes off in the high performance computing space, but it's doubtful. However, you can use Linux on the CELL.

For PCs, you will have to use the PPU for maximum performance. With Havok, their GPU tech is for non-critical physics only, which can be scaled back if the GPU is in heavy use. On the other hand, you can use the PPU for anything. Although, you could make an add-in card with a CELL on it and use that for physics, I don't think it will happen. Also, this will only be true for the next 4 years or so. After that, CELL-like specialised co-processors will be integrated directly on the main CPU, along with about 8 full out of order processers, and it will be retardedly fast. When that happens, you won't need a PPU, and you could probably get Geforce 6800 class graphics using the CPU alone.

[skumlex]

First of all it seems we agree that if you want awsome physics on the PC physx is the only choice NOW. But categorising the physx as an interim device that will only last 4 years could possibly be true, unless physics scale upwards just like graphics has (and we are not yet close to 100% picture quality where you can't tell game from reality). I can easily imagine going from 30.000 coliding objects to infinte colliding objects. Take a house made of more than 100.000 bricks, which are all physics objects, then imgaine a town, and its all destructable with real physics. That is a mad number of physics objects, so I belive the drive towards ever increasing realistic physics will require a specialised ppu, that in 4 years may have been upgraded once or twice.

Second of all I now that someone at IBM is currently working on getting linux to run on Cell, but for games Linux is not widespred enough to be a gaming platform.

I also doubt we will ever be in a situation where we won't need graphics cards anymore beacuse the cpu is powerfull enough.

If the Cell is indeed so powerfull why is there a Geforce 7800GTX installed alongside Cell in the PS3?

[DudeMiester]

You won't get infinite objects lol, unless you use some kind of procedurally generated environment, but that isn't really infinity objects, just potentially infinite objects. Anyways, unless we have the laws of physics totally wrong, which is a definite possibility, there's a fixed maximum amount of processing/information that can be contained in a volume of space.

Now as for the PPU being redundant, well if you could get the same effect simply by having another CPU, I think the industry would take that route. It will be undoubtably cheaper, given they will always be producing many more CPUs then PPUs. Personally, I think it's redundant, but useful in the current term. Unlike graphics, there isn't that many highly specific and specialised operations that physics requires. It's mostly standard CPU stuff, and hence I see no reason why a CPU couldn't do the job, but we'll see.

As for Linux, I don't know. Somehow I have a feeling that the PS3 OS will be based off Linux. I mean, given the comments by Sony that the HDD will come preloaded with Linux and all, it seems very likely. Although this is all speculation.

Finally, as for the 7800GTX. Originally, they did intend to use a second CELL for graphics, but unlike physics, graphics requires many specialised operations that arn't hardwired into the CELL. Hence, the performance was unacceptable, and so they opted for Nvidia's part.

[roryok]

I dunno about standalone physics processors. I mean, it sounds like a good idea, but what about the other aspects of gameplay? Are we gonna see an AI processor?

EDIT:actually I suppose thats the CPU, nevermind. Stoopid.

[skumlex]

The comment I made about infinite physics objects was more a figure of speach. Ofcourse the leveldesigner has to create and specify every physics object, so we wont get infinite but alot.

As to your remark about the industry going the path of a second cpu or a ppu. To repeat myself: a general purpose cpu like the one used in your pc now and in the near future will NOT be able to handle the same amount of physcis calcualtions as the physx. Not even the fastest AMD FX57 if it were dedicated to calculating physics alone. The reason ofcourse being that it isn't made for parallel computing, at least not the way the physx is. AMDs cpus can handle THREE instructions at the same time.

But you are rigt that CELL will be able to do physics, but that is beacuse it is engineered towards media intensive applications. Actually the Cell consists of only inorder cores, but since theres is 8+1 they can run in paralell. And thus handle physics calculations. (Read the article about the CELL on www.anandtech.com (http://www.anandtech.com) it is quite informative)

Oh and regarding whether it is more difficult to program for multithreaded hardware. John Carmack (Who is very much still coding and hence by your definition NOT an idiot) said that the PS3 is more powerfull than XBOX360 but also more difficult to program for.

[hell-angel]

What skumlex said plus the fact that the PPU has the calculations harcoded in the hardware which means it will run faster as well. So it will definately be usefull, I don't think I want to spend 200 euro on it though. http://forums.3drealms.com/ubbthreads/images/graemlins/smile.gif

[DudeMiester]

Well that's the thing, in order to keep flexibility high, you can't hardcode all the algorithims. Because of all the types and configurations of objects, there's no way to incorperate logic for all the possible combinations. You're better off just building a bunch of simple, but flexible, processors.

About the CPU, I'm talking down the road 4 years, when you have 8+ Athlon FX-57s at your disposal, in which case you will have enough computational power. On the other hand, if they expose the PPU as the general purpose co-processer that it is, instead of hiding it behind an API, I suppose it could be useful in the long term, but only as an alternative way to add another CPU to your system.

As for coding it, I never said it was easy, but it's not so hard as people like Gabe Newell make it out to be.

[hell-angel]

DudeMiester said:
Well that's the thing, in order to keep flexibility high, you can't hardcode all the algorithims. Because of all the types and configurations of objects, there's no way to incorperate logic for all the possible combinations. You're better off just building a bunch of simple, but flexible, processors.



True, but there are also a lot of standard things which can be hardcoded (like fluid simulations) so that is most likely what they implement. I am not sure though.

[roryok]

If the ppu is just an auxiliary CPU hidden behind an API....


What about using a dualcore processor, one core handling AI/loading etc, the other handling Physics? wouldn't it be a boatload more powerful than any standalone ppu?

[hell-angel]

roryok said:
If the ppu is just an auxiliary CPU hidden behind an API....


What about using a dualcore processor, one core handling AI/loading etc, the other handling Physics? wouldn't it be a boatload more powerful than any standalone ppu?



That depends, you must remember that the PPU does a lot of things in hardware mode a normal CPU can't do. and since HW mode is much faster then normal mode it might balance out. Besides you still need a normal CPU for that AI/loading part so it will allways be a dual core setup. http://forums.3drealms.com/ubbthreads/images/graemlins/smile.gif

[roryok]

hell-angel said:

roryok said:
If the ppu is just an auxiliary CPU hidden behind an API....


What about using a dualcore processor, one core handling AI/loading etc, the other handling Physics? wouldn't it be a boatload more powerful than any standalone ppu?



That depends, you must remember that the PPU does a lot of things in hardware mode a normal CPU can't do. and since HW mode is much faster then normal mode it might balance out. Besides you still need a normal CPU for that AI/loading part so it will allways be a dual core setup. http://forums.3drealms.com/ubbthreads/images/graemlins/smile.gif



true, hadn't thought about the HW angle.

Still tho, would kick ass to have a seperate core for physics, lost of stuff would be doable. Altho it'd be tough to scale it down for single core CPUsers

[DudeMiester]

Well normal CPUs have a lot of extra stuff like the x86 front end, OoO processing, register remapping, complex multi-tier caches, etc... You don't need these things in a PPU, they just take up space. A CPU needs them because it needs to be backwards compatible and run all sorts of badly written code, lol. On a PPU you can spare a number of those things to pack in extra processors. Then again, you can also stick simple processors on the side of a complex one, like how the CELL does too. This is where CPUs are headed.

[hell-angel]

roryok said:
Still tho, would kick ass to have a seperate core for physics, lost of stuff would be doable. Altho it'd be tough to scale it down for single core CPUsers



True, but that would then be treathed the same as the GPU, it gets required. But that will take some time though. http://forums.3drealms.com/ubbthreads/images/graemlins/smile.gif