PS3 GPU Analysis

[version]

http://www.ottawaphotonics.com/news/FibreFeb05/nvda0217.pdf

 

[V3]

think Marconelly meant the UMA/ system RAM bandwidth but I maybe mistaken.

Yeah, that's what I thought. I always assumed PS3 would use some kind of EDRAM too, so I couldn't understand why DemoCoder seems so staunchly opposed to that, when Xbox 2 already seems to have simillar memory configuration.

It's because NV GPUs are typically without eDRAM and the Sony and NV deal was assumed to be made just recently. So at this point the most probable case is PS3 GPU without eDRAM.

My thinking at the moment is, if there are eDRAM, it won't the exotic kind like the one in PS2 GS.

 

[one]

http://www.ottawaphotonics.com/news/FibreFeb05/nvda0217.pdf

OK, then a logical guess leads to

1. The nVIDIA royalty for the PS3 per unit is under $5.
2. The PS3 will be released in 2006.

 

[Pozer]

1. The nVIDIA royalty for the PS3 per unit is under $5.
2. The PS3 will be released in 2006.

Thats hilarious so Sony/Nvidia would have to sell around 60 million PS3s to make what the made off the xbox gpu, which was estimated at around $25-30 I believe..(60 mill is very possible too if it spanks x2 in power and marketed right). Wonder why they claim the xbox deal wasn't profitable for them. Probably had to allocate less engineers. Wonder what they got for desinging xbox mainboard and MPU other than PC distro rights. Interesting..... thinking out loud again......

 

[3dcgi]

1. The nVIDIA royalty for the PS3 per unit is under $5.
2. The PS3 will be released in 2006.

Thats hilarious so Sony/Nvidia would have to sell around 60 million PS3s to make what the made off the xbox gpu, which was estimated at around $25-30 I believe..(60 mill is very possible too if it spanks x2 in power and marketed right). Wonder why they claim the xbox deal wasn't profitable for them. Probably had to allocate less engineers. Wonder what they got for desinging xbox mainboard and MPU other than PC distro rights. Interesting..... thinking out loud again......

Are you sure you're not confusing revenue and profit. PS3 royalty is pure profit. Xbox included the cost of the chip which Nvidia paid for.

 

[a688]

1. The nVIDIA royalty for the PS3 per unit is under $5.
2. The PS3 will be released in 2006.

Thats hilarious so Sony/Nvidia would have to sell around 60 million PS3s to make what the made off the xbox gpu, which was estimated at around $25-30 I believe..(60 mill is very possible too if it spanks x2 in power and marketed right). Wonder why they claim the xbox deal wasn't profitable for them. Probably had to allocate less engineers. Wonder what they got for desinging xbox mainboard and MPU other than PC distro rights. Interesting..... thinking out loud again......

Are you sure you're not confusing revenue and profit. PS3 royalty is pure profit. Xbox included the cost of the chip which Nvidia paid for.

How much is nVidia getting paid to modify their chip for the PS3?

 

[3dcgi]

How much is nVidia getting paid to modify their chip for the PS3?

I don't know, but as that's a non-recurring cost it probably isn't included in the less than $5 per chip estimate. There probably would have been the same type of non-recurring payment for Xbox too.

 

[j^aws]

So I take the STRONG/ WEAK arguments fell apart at the first hurdle with eDRAM then?

 

[marconelly!]

It's because NV GPUs are typically without eDRAM and the Sony and NV deal was assumed to be made just recently.

Isn't it the same situation with ATI? How many GPUs with EDRAM have they made?

I guess if the EDRAM is the way of the future, they will both have to switch to it eventually. Also, as far as I can see, that kind of change cannot be gradual, so saying that they never did it before doesn't add much to the argument (at least it seems that way to me)

 

[Inane_Dork]

It's because NV GPUs are typically without eDRAM and the Sony and NV deal was assumed to be made just recently.

Isn't it the same situation with ATI? How many GPUs with EDRAM have they made?

1, at least.

 

[one]

BTW, it was almost confirmed that the PS3 GPU has eDRAM by the Nikkei Microdevices magazine. The Cell will be produced in the 90nm SOI process and the GPU will be produced on bulk-silicon with eDRAM. The mass production is well on schedule, apparenly.

 

[nAo]

BTW, it was almost confirmed that the PS3 GPU has eDRAM by the Nikkei Microdevices magazine. The Cell will be produced in the 90nm SOI process and the GPU will be produced on bulk-silicon with eDRAM. The mass production is well on schedule, apparenly.

That's a huge news! any link?

 

[one]

BTW, it was almost confirmed that the PS3 GPU has eDRAM by the Nikkei Microdevices magazine. The Cell will be produced in the 90nm SOI process and the GPU will be produced on bulk-silicon with eDRAM. The mass production is well on schedule, apparenly.

That's a huge news! any link?

No link The magazine homepage is here but doesn't contain it.
How much eDRAM can they put on the 90nm process, anyway?

 

[nAo]

No link The magazine homepage is here but doesn't contain it.

How do you know then?

How much eDRAM can they put on the 90nm process, anyway?

The real question is...what is GPU transistors count?
IMHO 500+ MTransistors is a good approximation. eDram can be very dense and Sony has a lot of experience with eDram.
32 MB would be a sweet spot, but I believe we are going to have something like 16 MB. If they follow the same route as PS2 with GS I expect textures to be uploaded on GPU edram, even if it would be nice if the GPU could texture even from external memory.

 

[V3]

It's because NV GPUs are typically without eDRAM and the Sony and NV deal was assumed to be made just recently.

Isn't it the same situation with ATI? How many GPUs with EDRAM have they made?

Well only the one in Gamecube. But I think Democoder, is assuming it will be like NV2a chip in Xbox. Which not a bad assumption, IMO.

I guess if the EDRAM is the way of the future, they will both have to switch to it eventually. Also, as far as I can see, that kind of change cannot be gradual, so saying that they never did it before doesn't add much to the argument (at least it seems that way to me)

eDRAM has a tradeoff to it. Its not a win win solution just yet. Maybe in the future, but not next gen.

 

[V3]

BTW, it was almost confirmed that the PS3 GPU has eDRAM by the Nikkei Microdevices magazine. The Cell will be produced in the 90nm SOI process and the GPU will be produced on bulk-silicon with eDRAM. The mass production is well on schedule, apparenly.

That's a huge news! any link?

No link The magazine homepage is here but doesn't contain it.
How much eDRAM can they put on the 90nm process, anyway?

You should be able to put 16 MB. More depending on the NV GPU too.

BTW, where is Vince ? Is he Banned or something ? I wonder if he has some inside info to what ever happend to the 65 nm process.

 

[nAo]

16 MB of edram need something like 130+ MTransistors, moreover if PS3 GPU doesn't have any vertex shader engine most of remaining transistors budget would be employed in a number of pixel shading engines.
NV40 has 220 Mtransistors with 6 VS, 16 PS and a video processor, so it shouldn't be unfeasible to have a GPU with 32 pixel pipes , no vertex pipes and 16 Mb of edram for something like 400-500 MTransistors.
Dunno what are the opportunities to have a few of fat pixel pipes with a lot of ALUs per pipe or more light pipes...
[EDIT] Vince is writing on PSINext forums..

 

[Shifty Geezer]

How many pixel pipes are needed? How many effects can one actually have before they become unnoticeable? Can any describe a situation where 32 pixel pipes are going to be fully active?

 

[nAo]

How many pixel pipes are needed?

more is better, if all the architecture is well balanced.

How many effects can one actually have before they become unnoticeable?

What

Can any describe a situation where 32 pixel pipes are going to be fully active?

Most GPUs work in quads (2x2 pixels), quad are assigned to different primitives and tiles of the render target, so in the common case all the pipes should be active most of the time.

 

[Fafalada]

If they follow the same route as PS2 with GS I expect textures to be uploaded on GPU edram, even if it would be nice if the GPU could texture even from external memory.

I think it's more likely they'd follow a more recent GPU memory design then GS, if they followed any of their own at all
With that in mind, ideally eDram would be setup like real scratchpads work on CPUs - GPU can read its data from both memories, one is just faster and doesn't steal the bus

It's nice for balancing memory speeds without a ton of manual labor, still has all the benefits of 'free' render to texture ops, and if the GPU can vertex shade, you can dump frequently used geometry in eDram too.
And it's way more convenient with limited amount of fast mem, like 16MB or so, then GS like setup would be (I would want 64MB if we got the latter).

Dunno what are the opportunities to have a few of fat pixel pipes with a lot of ALUs per pipe or more light pipes...

I guess if you're a fan of shadow volumes and postprocessing fun, you'd probably want more lighter pipes.