So is R580 supposed to be 48 pipes or 48 ALUs?

Inquirer / Fuad about R580:
21. 03. 2005: "same number of pipelines, similar specifications, but a faster card"
09. 06. 2005: "Whatever happens with R520, R580 will have all 32 pipelines enabled."
30. 08. 2005: "We don’t expect that it (R580) will be just have a different number of pipes, it might have a few changes"
04. 11. 2005: "ATI will add more pipes to R580 and it will get back in the game, aiming for the performance crown."
14. 12. 2005: "ATI's R580 has 16 pipelines but 48 Pixel Shader units" - finally correct info about R580!

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Beyond 3D forum / caboosemoose:
22. 03. 2005: "my information describes R520 as: 16-1-1-1 and R580 as 16-1-3-1"

...9 months earlier than The Inquirer

 

Yeah. Its good to know that the Inq has known what they have been talking about all this time.

LVS

 

Thank you fans. No autographs, please.

 

Oooh pleeeeaaaaase. I could sell it on Ebay.

 

Well, the point being is that Fudo probably earnt a reasonable amount of money for each article submitted; caboose got f' all!

 

I'd say that's Mike Magee's problem to rectify. How many people out there would stop taking a paycheque for doing a job poorly while being held accountable for nothing?

P.S. By the way, caboose, what's your info saying about R600?

 

I think Fudo sometimes knows more than he's letting on, but that doesn't mean he has to let you know that straight away.

 

So, thats Kudo's and Mulo for Fudo's FUD? is that about right Dave?

I think it takes a real Moose to tell the truth and not expect anything in return

 

Uh oh....there's a higher degree of "nothing" <shrug>

 

Or it might be he's covering all his bases.

Says this, says that .. hey .. one of them has to be right. Right!?



US

 

For once I thought the Inquirer had something insightful to ask today. It hasn't happened before so they must be learning as they poach points of view from the folk here at Beyond3d.

The article in question (below) had the insight that ATI goes for fewer, busier, higher clocked pipes with a 3:1 texture unit to pixel shader ratio - whilst NVidia backs slower pipes but more of them and a 3:2 TMU : Pixel Shader ratio. The Inq postulated that those differing ratios might make it quite hard for a game developer to generally optimise games given the majors have different balance points.

I'd love a game developer to respond to that...

http://www.theinquirer.net/?article=28341

ATI's R580 has 16 pipelines but 48 Pixel Shader units

BACK IN September, ATI told us that you need more per pixel operations then you need textures. It’s the ratio that changed over the years, but we don’t want to make a history class of this article. It said that it believes that the industry should go that way. Nvidia, on the other hand, believes in different ratios between pixels and textures.
We finally confirmed that ATI's upcoming R580 GPU will again have sixteen pipelines only but this time it will have 48 Pixel Shader units. What does that mean?

Well, it's not the easiest subject to explain, but pipelines in this case can be associated with a job done by texture memory units.

In the R580 case, the chip has 16 traditional pipelines that can process 16 textures while at the same time it can calculate 48 pixel data. The RV530 marchitecture is a good way to understand what ATI is doing now. With this chip, you have 12 pixel Shaders but just four texture memory units. Its a 3:1 ratio, as ATI believes that you need that many pixel information compared to textures.

In R520 for example ATI is using 16 pixel shaders, pipelines and has 16 matching texture memory units. In perfect scenario in each clock you can get 16 textures over 16 pipelines. Nvidia's G70 has 24 pipelines, let's call them pixel Shaders but it can process 16 textures. Nvidia is using a 3:2 ratio, as it believes that just need a little bit more pixels than textures.

We strongly believe that Nvidia is going to increase the number of its pixel operations and texture units in its upcoming G71 GPU. We believe it might move to 32 pixels/pipelines and 24 TMUs but we cannot confirm this at press time.

This might bring us back to the times when graphic companies will pressure developers to program for their hardware. It will be their choice to use 3:2 Nvidia's pixel to texture ratio or 3:1, which is what ATI wants to do. Nvidia spends more money in its TWIMTBP, The Way Its Meant To Be Played so it might win more of these battles

 

I'd love to have those supposed 3:2 or whatever ratios explained on GeForces *snicker*

 

I think the inquirer is confusing texture units with rops.
G70 has 24 pipes, but only 16 rops, a 3:2 ratio.

 

Gaining tidbits of information is half of what you'd need for any sort of supposed journalism; the other half would be the ability to decypher said information otherwise it's useless.

 

Wow, that's just....stupid. But it's what I've come to expect from the Inquirer. Just like the Radeons, GeForces have always been capable of executing more math operations than texture operations per clock (even back before pixel shaders).

 

I don’t think it would make much sense to triple the shader power from the R520 to R580. I think the die size would be unmanageable.

Even going to 48 single full-ALU’s would give the 580 a minimum of 50% more shader power (48 vs 32 -- 16 full-ALU + 16 mini-ALU’s) over the R520. Probably quite a bit more when one factors in how efficiently the second mini-ALU can be used on the current R520.

 

It's already been established that R580 has/will have 3 times the (theoretical) shader power of R520.

 

Efficient shader compilers are harder to write than you think they are.

Uttar

 

I read the whole thread. I didn’t see anywhere where is was confirmed that the R580 would have triple the shader power (unless I missed that).

My thinking is that one could avoid the inefficiencies of parallelism in putting a mini-ALU with a full-ALU by just going with lots of single ALU’s.

How much extra shader power does the mini-ALU add in real world situations considering it both -- has to work in parallel with the full-ALU, and is a mini-ALU to begin with and can’t handle all types of calculations.

If the 16 mini-ALU’s (R520) add … lets say 60% (a guess) more real world shader power to the full ALU’s. Then they would add that to the R580. 3.0/1.6 = 1.875 … the 48 single full-ALU’s would have 87.5% more shader power in real world situations over the R520. Almost double -- it would depend on how efficient those second mini-ALU’s are. I think doubling the shader power over the R520 would be considered a large jump in overall shader power.

 

"I read the whole thread. I didn’t see anywhere where is was confirmed that the R580 would have triple the shader power (unless I missed that)."

Imagine the X1600 with 4 times the ROPs and 4 times the ALUs thats basically the R580.