PPPs`PPUs and Raytracing Units: next-next gen consoles?

[Megadrive1988]

Since the new consoles are basicly finished (Xenon) or probably nearing completion (Revolution, PS3) I assume it is much too late in the game for them to have had Primative Processing Units, Physics Processing Units and Raytracing Units/Engines implemented, so those things would come, if at all, in the next-next generation: Xbox3, N6 and PS4.


And while some might argue that CPUs can do the job of PPUs, and GPUs can do the jobs of PPPs and RTUs, others would argue that general purpose silicon will not match the performance of dedicated purpose silicon.


what about a middle ground? why not integrate PPUs into next-next gen CPUs and integrate PPPs and RTU/Es into next-next gen GPUs, if they are not already going down that route.

 

[ERP]

Doesn't it all depend on what thaty fixed function hardware actually does?

If realtime raytracing becomes a requirement, you'll see GPU's move towards a model that will better solve that problem. Right now they are not well suited to it.

Similarly if whatever the Physics processor actually does in hardware provides a real benefit, then you'll see migration to CPU's or GPU's that provide accelleration for subsets of that.

I don't see these types of specialised hardware having a long lifetime, if they ever make the mainstream at all, but I've been wrong before.

Pure speculation but I think you'll find that something like a "hardware raytracer", or "physics accellerator" are much more like modern general purpose CPU's with specialised logic for recurrent problems than like modern GPU's which exist because a stream architecture is almost Ideal for graphics, and very bad at running word.

 

[Acert93]

The Ageia (sp?) Physics Processing Unit has ~125M transistors. The CELL shown last month had ~230M transistors.

Rough guestimates: In 2011-2012 if they are at 32nm or ~22nm process (assuming 65nm in late 2005, 45nm in 2007, and 32nm in 2009, and maybe low 20s in 2011) we would be looking at 8-16x as many transistors per die compared to this generation. That is a lot of assuming (i.e. it is taking longer to shrink the processes down and that would be nearing the "wall", no delays, a desire to put as many on as possible at a set die size, and not going with a 2010/early 2011 launch). So lets say, realistically, we are looking at 8x as many transistors. This is all guessing, so you can pretty much ignore this...

It is about tradeoffs--you are talking about a device with half as many transistors as the entire CPU. At currently levels you would be looking at trading off realestate for maybe 4-6 SPEs for this--but we all know by 2011 that the PPUs will be 2-4x larger. So basically you would be giving up 1-2 CELL processors to incorperate this type of device.

Which is better: A 8 CELL processor or a 6 CELL + 1 PPU processor?

Looking at Sony's gameplan I would say sticking with the all CELL design. Developers are going to spend the next 5-6 years writing a ton of code--physics, AI, geometry, etc...--code for the SPEs. Introducing a new unit for physics defeats the purpose of all the power the SPEs have and in 6 years it wont really matter. Sony is pushing the streaming design and the MORE CELLS they have the better. And CELLs are multipurpose, so that is another plus.

I would think the PPUs would be a good idea for MS and Nintendo to look at though. Whereas the "CELL in everything" will help Sony cut costs on CELL, with MS and Nintendo using specialized HW that has a good costerformance ratio is a good move (especially since they have to pay to have this stuff fabbed). Although, from recent comments about the R500 and how programmable it is, by 2011 GPUs may be so flexible and multipurpose that physics may be something joined at the hip.

I am excited about the Physics Processing units. It will be interesting to see if ATi or nVidia gets a wild hair and tries to move in on this market also. I think it would be great if GPUs offered PPUs onboard. I know I would pay another $50-$100 for a PPU on my graphics card if it was something the GPU vendors were pushing developers to support.

 

[Brimstone]

For the upcomming gen, has it been proven that Aegia PPU won't be in the X-Box 2? We know the XNA SDK is going to support it, the Unreal 3 engine is definatley going to take advantage of it on the PC side, and ex-Microsoftie Ed Fries sits on the board.

 

[Megadrive1988]

there have been alot of hints that Xenon might have a PPU incorporated into it. not just the SDK but the actual, or an actual PPU unit. I kinda doubt it but you never know. if it was there, it would certainly be MS's technology ace in the hole to counter Cell. not that Xenon even needs a PPU, im sure it'll be fine with the multicore CPU and ATI GPU. bah, im just babbling.

 

[Brimstone]

there have been alot of hints that Xenon might have a PPU incorporated into it. not just the SDK but the actual, or an actual PPU unit. I kinda doubt it but you never know. if it was there, it would certainly be MS's technology ace in the hole to counter Cell. not that Xenon even needs a PPU, im sure it'll be fine with the multicore CPU and ATI GPU. bah, im just babbling.

Rumors a while back hinted at a 3rd chip. Since Aegia seems to have major financial backing, I would assume one of the early business model goals would be to get into a console. It would decrease the risk involved in funding such a start-up. Companies just don't investment money into companies like Aegia without a lot of scrutiny.

 

[Megadrive1988]

there have been alot of hints that Xenon might have a PPU incorporated into it. not just the SDK but the actual, or an actual PPU unit. I kinda doubt it but you never know. if it was there, it would certainly be MS's technology ace in the hole to counter Cell. not that Xenon even needs a PPU, im sure it'll be fine with the multicore CPU and ATI GPU. bah, im just babbling.

Rumors a while back hinted at a 3rd chip. Since Aegia seems to have major financial backing, I would assume one of the early business model goals would be to get into a console. It would decrease the risk involved in funding such a start-up. Companies just don't investment money into companies like Aegia without a lot of scrutiny.

exellent point.

hmmm

 

[Shifty Geezer]

Rumors a while back hinted at a 3rd chip. Since Aegia seems to have major financial backing, I would assume one of the early business model goals would be to get into a console. It would decrease the risk involved in funding such a start-up. Companies just don't investment money into companies like Aegia without a lot of scrutiny.

They did Infinium! That's the point of Venture investment - high risk for high gains. Just seeing they've got backing isn't a sign of major contracts already. There have been millions of startup companies with new ideas/inventions and financial backing, which have folded. I can see the market for Aegia's PPU, but whether they succeed in it is a different matter. What prices their silicon? How likely will people buy another addon for their PC? Will there be any benefit if games' physics engines need to run on, and are thus limited to the performance of, non-PPU hardware?

Um, a bit off track there. Anyway, yeah they've got backing - that's no indicator in itself AFAICS. Given its apparent huge memory requirements I can't see it making it's way into a console, though the possibility is there and might make up for some of that Teraflop Xenon performance.

 

[Acert93]

Um, a bit off track there. Anyway, yeah they've got backing - that's no indicator in itself AFAICS. Given its apparent huge memory requirements I can't see it making it's way into a console, though the possibility is there and might make up for some of that Teraflop Xenon performance.

What memory requirements? The PC version will have 128MB of memory on card.

But it would be totally silly comparing the PC version to the console version. This is like saying an acceptible gaming PC requires at LEAST 512MB of memory and 128MB of video memory MINIMUM--and then applying that to Consoles.

It does not work that way. We are looking at next gen consoles having unified memory architectures where the GPUs and CPUs share a pool of common memory. There is absoluately nothing stating that a PPU could not be introduced into such a setup if such a chip was included in the initial design plan.

On a tangent, we are not currently aware of WHY the chip needs its own memory. You would think that possibly it could share the systems memory over PCIe. But when you consider GDDR3 memory has a bandwidth of 20-35GB/s and system memory is in the 3.2-6.4GB/s range--and shared among the system--that alone makes a good case of WHY it would need its own memory pool. It looks like it is meant to offload all the physics which with 30,000-50,000 rigid body objects intereacting in realtime would require a lot of memory bandwidth. Fighting the system memory, which is already limited, would bottleneck the performance. It is like comparing a two identical chips (e.g. NV40), one on PCI using system memory and the other on 8x AGP with its own GDDR3 memory.

So just as memory hungry/bandwidth intensive GPUs can play nicely on consoles but not on PCs, a similar situation may exist on the consoles. We do not know--and the very reason stating that the PC memory setup possibly precludes its inclusion on the console.

I do see 2 reasons why I see it difficult to believe this is in.

1) A 125M transistor chip requiring 25W of power would add additional cost and heat.

2) With all the rumblings about how flexible the GPU is, it does give you pause to consider the possibility if the GPU can do this type of work. If the answer is "Yes" then I would wonder why not just add another GPU and allow developers to choose what they do with it. I find this a less likely option (especially a 350M transistor chip) but so far we have based all our understandings of the system on a supposedly accurate OLD leak and ATi/nVidia are moving to multiple chips, so who knows.

In the end I would like to see the Ageia chip in a console because it would mean an increased chance it would catch on in the PC sector, but I think we wont know too much more until May.

 

[Shifty Geezer]

Given its apparent huge memory requirements I can't see it making it's way into a console, though the possibility is there and might make up for some of that Teraflop Xenon performance.

What memory requirements? The PC version will have 128MB of memory on card.

It does not work that way. We are looking at next gen consoles having unified memory architectures where the GPUs and CPUs share a pool of common memory. There is absoluately nothing stating that a PPU could not be introduced into such a setup if such a chip was included in the initial design plan.

I didn't mean the chip needs it's own RAM, only lots of it! On next gen, whatever RAM there is needs to go on display, textures, code, AI, models, etc. Lots of content. And physics, whether there's a PPU or not. For a PPU capable of umpteen thousand rigid bodies, it needs 128mb RAM available. That's too much of the pie it would seem. If it doesn't have that much available it won't (presumably) be able to process as many rigid bodies.

I'd say they could include a PPU of a smaller variety perhaps, less power but less memory hungry, to relieve burden from the CPU.

BUT...what're those 3 PPC cores to do then? There's a GPU for graphics and a PPU for physics. You've now got 90/120/360/1000 gigaflops CPU performance with nothing but game code and AI to worry about. And maybe audio. MS wouldn't have put in that much CPU performance if it wasn't justified. That means giving it something to work on, and the big performance drains I see are AI and physics. Given this and the memory consumption of a seperate PPU, there seems no point to it in the Xenon framework. Otherwise I don't know how they'll use the meaty processor.

 

[Urian]

XeCPU and PS3 Cell CPU are custom CPU, the cost of a custom CPU is more higher than a non-custom CPU but it has better performance in some ways.

The console that has more numbers for it is Nintendo Revolution, Nintendo never used a custom CPU, they always used a low cost cpu for the system since the NES days and I believe that this won´t change in Revolution, a combo CPU+PPU could be good in Revolution if Nintendo takes a non-custom CPU.

 

[Acert93]

I didn't mean the chip needs it's own RAM, only lots of it! On next gen, whatever RAM there is needs to go on display, textures, code, AI, models, etc. Lots of content. And physics, whether there's a PPU or not. For a PPU capable of umpteen thousand rigid bodies, it needs 128mb RAM available. That's too much of the pie it would seem. If it doesn't have that much available it won't (presumably) be able to process as many rigid bodies.

Like I said, the memory requirement may be more Bandwidth related than size constrained. On a console the bandwidth is not only higher, but consoles have shown that a GPU and CPU can play nicely with a UMA. A PPU designed to work natively and effeciently should be no more of a problem than have a Vector or SPE unit working on the same task.

That being said, if the memory size is the problem then do not expect the X2, PS3, or Rev to do a lot of physics--at least not on the scale of the Ageias chip.

BUT...what're those 3 PPC cores to do then? There's a GPU for graphics and a PPU for physics. You've now got 90/120/360/1000 gigaflops CPU performance with nothing but game code and AI to worry about. And maybe audio. MS wouldn't have put in that much CPU performance if it wasn't justified. That means giving it something to work on, and the big performance drains I see are AI and physics. Given this and the memory consumption of a seperate PPU, there seems no point to it in the Xenon framework. Otherwise I don't know how they'll use the meaty processor.

I think you are right that the 3 core X2, especially if it has 3 Vector Units, will be pretty powerful. But looking at the X2 design, the R500 is said to be able to do tasks not generally done by GPUs. And the CPUs can take some of the Vertex load--so the system is pretty flexible. When you consider that the CPUs may be doing some vertex shading, AI, physics, game logic, Audio, and other general tasks it may be too much to (A) do all they want in the physics department and (B) not enough compared to the PS3 SPEs (although the SPEs will be doing all the major game code + probably all the vertex shading, so that is only a "what if") so there is room to see MS including a PPU if they felt it necessary to compete.

But I see that hard to believe. X2 and PS3 are really different designs. Everyone wants to focus on the CELL and the GFLOPS, but when you look at the flexibility of the X2 and what the CELL will be asked to do--and then compare general architectures--I think we tend to blow things out of perportion. e.g. Going by GFLOPS alone you would think that the PS2 was the most poweful machine, but Xbox seems to flex its muscles more times than not. Yet even the GCN can put out games that totally wow gamers...

Anyhow good points Shifty.

 

[Brimstone]

BUT...what're those 3 PPC cores to do then? There's a GPU for graphics and a PPU for physics. You've now got 90/120/360/1000 gigaflops CPU performance with nothing but game code and AI to worry about. And maybe audio. MS wouldn't have put in that much CPU performance if it wasn't justified. That means giving it something to work on, and the big performance drains I see are AI and physics. Given this and the memory consumption of a seperate PPU, there seems no point to it in the Xenon framework. Otherwise I don't know how they'll use the meaty processor.

Digital Geometry Processing?

 

[pc999]

1

Anyone have a idea of who many bodys can a 4 SPUs control

 

[Megadrive1988]

XeCPU and PS3 Cell CPU are custom CPU, the cost of a custom CPU is more higher than a non-custom CPU but it has better performance in some ways.

The console that has more numbers for it is Nintendo Revolution, Nintendo never used a custom CPU, they always used a low cost cpu for the system since the NES days and I believe that this won´t change in Revolution, a combo CPU+PPU could be good in Revolution if Nintendo takes a non-custom CPU.

that is not entirely true. the Gekko CPU for Gamecube was somewhat custom. although Gekko was based on a G3 (PowerPC 750CX) the Gekko was in development for quite awhile. it had quite a few improvements to enhance its performance for console gaming. the bus. the cache, and a completely new (iirc) SIMD unit, among other things. although the Gekko is not completely built from scratch, it is alot more custom than the L2 cache-halved PentiumIII in Xbox, which had extremely few if any customizations. compared to a standard PIII.

 

[archie4oz]

XeCPU and PS3 Cell CPU are custom CPU, the cost of a custom CPU is more higher than a non-custom CPU but it has better performance in some ways.

The console that has more numbers for it is Nintendo Revolution, Nintendo never used a custom CPU, they always used a low cost cpu for the system since the NES days and I believe that this won´t change in Revolution, a combo CPU+PPU could be good in Revolution if Nintendo takes a non-custom CPU.

that is not entirely true. the Gekko CPU for Gamecube was somewhat custom. although Gekko was based on a G3 (PowerPC 750CX) the Gekko was in development for quite awhile. it had quite a few improvements to enhance its performance for console gaming. the bus. the cache, and a completely new (iirc) SIMD unit, among other things. although the Gekko is not completely built from scratch, it is alot more custom than the L2 cache-halved PentiumIII in Xbox, which had extremely few if any customizations. compared to a standard PIII.

There is no SIMD "unit" in Gekko, the FPU is modified to allow execution against packed floats... And there isn't really any modification to the CPU in Xbox, it's not a PIII, it's a mobile Celeron (check it's S-code)... AFAIK the only thing different from an off-the-shelf part is the packaging...

 

[Megadrive1988]

XeCPU and PS3 Cell CPU are custom CPU, the cost of a custom CPU is more higher than a non-custom CPU but it has better performance in some ways.

The console that has more numbers for it is Nintendo Revolution, Nintendo never used a custom CPU, they always used a low cost cpu for the system since the NES days and I believe that this won´t change in Revolution, a combo CPU+PPU could be good in Revolution if Nintendo takes a non-custom CPU.

that is not entirely true. the Gekko CPU for Gamecube was somewhat custom. although Gekko was based on a G3 (PowerPC 750CX) the Gekko was in development for quite awhile. it had quite a few improvements to enhance its performance for console gaming. the bus. the cache, and a completely new (iirc) SIMD unit, among other things. although the Gekko is not completely built from scratch, it is alot more custom than the L2 cache-halved PentiumIII in Xbox, which had extremely few if any customizations. compared to a standard PIII.

There is no SIMD "unit" in Gekko, the FPU is modified to allow execution against packed floats... And there isn't really any modification to the CPU in Xbox, it's not a PIII, it's a mobile Celeron (check it's S-code)... AFAIK the only thing different from an off-the-shelf part is the packaging...

ok then I stand corrected. my point was, that Gamecube's Gekko CPU is more customized than Xbox CPU.

 

[nelg]

there have been alot of hints that Xenon might have a PPU incorporated into it. not just the SDK but the actual, or an actual PPU unit. I kinda doubt it but you never know. if it was there, it would certainly be MS's technology ace in the hole to counter Cell. not that Xenon even needs a PPU, im sure it'll be fine with the multicore CPU and ATI GPU. bah, im just babbling.

Do you think that MS could leverage the IP they got from ATI to develop something similar to the Ageias chip? Add it to the CPU and use it for other things as well (geometry?)?