R520 - talk, rumours, speculation; the lot!

Indeed. There's not much "interesting features" you can put there. Maybe changes are related to antialiasing (the rasterizer is the part that determines sample coverage), or maybe they dropped the triangle clipping stage and use infinite guardband clipping instead. My guess would be they changed the tiling mode.

I don't think so.

 

Would it rain mockery on my fevered brow if I asked: TBDR?

Obviously they went aways that direction in C1, but then they had the eDram max size factor to deal with there. One would assume for R520 the advantage would be bandwidth in a bandwidth-starved world. . .but then I don't know how much advantage is still left there given all the Z optimizations that have developed over recent years.

 

Not deferred rendering. I meant the mode of tile distribution, i.e. each quad pipeline working on fixed screen tiles in current chips (and supertiling on top of that).

 

I can't imagine there's much to improve with rasterisation. R420 already has programmable tile sizes so I doubt it's along those lines.

Could it relate to batching? Sigh, we don't seem to know how ATI cards batch.

Jawed

 

absolutly no chance. Unified Shaders is something WGF2.0 will utilize and utilize alone. Wouldnt make sense at all for them to release a WGF2.0 card when WGF2.0 doesnt even have a launch forseen. Plus i think they'd have to get the go ahead from microsoft on something that far ahead and key to Longhorn, which i doubt they'd get. Basically what im getting at is it would be a bragging right only even if it were a chance, but a performance boost most certainly wouldnt be there without heavily modified and powerful pipes under the hood to begin with. Nothing is hinting toward unified shaders.
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isnt a new rasteriser a given considering the rather large change to the feature set the core supports?

 

There are hints towards it. I wouldn't truely take a stance like this without hints, and its possible to come out with a a card that supports new features without the API coming out. Look at dx9c and nV's sm3.0 cards. What was it 3 to 5 months it took for nV to get sm 3.0 dirvers and dx9c testing for whql. 3 to 5 months from early 2006 will lead to possibly right around the release of Vista.
If I'm wrong, thats ok, its just a guess.

 

Yup. Just have a look at the R300 and DX9. ATI had the cards out several months before the API was out. Not to mention them supporting instancing even though it wasn't supported/exposed in the API until years later.

 

very true

 

i guess the big thing that makes me not believe it is the simple reason of why waste all this time on it if its that. And this isnt DX9C or a user end update, its a whole new OS as far as i know. Longhorn isnt even going to launch with 2.0 thats going to come, who the heck knows when, and its suppose to be very big in changes, not just unified shaders and SM4.0. I guess i just dont see the strategic sense in wasting time for it unless it will make the R520->R600 transision that much easier? Certainly would be a shock, and i'd think it was cool, but i just dont see it. Longhorn is still on track for a Q4 2006 release i think right, or did they slip something in that Vista preview thing they did.

 

Vista is longhorn I think it was Q4, and most likely it will come out then too, but WGF will support both traditional pipelines and unified. ATi already has a unified pipeline structure with the xbox 360 chip. They could easily just control a chip like that through drivers to perform similiarly to a chip with traditional pipeline, probably don't have to though.

 

You seem to forget that vista will not launch with WGF2.0 but with WGF1.0 also all the new effects in vista will be programmed for WGF1.0
WGF2.0 still seems very far away, launching probably 6 months or more after vista.

 

http://www.rage3d.com/board/showthread.php?p=1333818374#post1333818374

This guy believes he has the answers.

 

I'm sure a lot of people believe they have the answers.

 

Well, with the number of stupid reports around I'm sure they will.

 

Considering r520 is still based on r300 architecture. I'm wondering how much of a problem would it be to detach the ROP's from the fragment pipeline for ATI? Nvidia had their chips designed for a long time now like that so it isn't a problem but Ati never had such a design.

One reason i believe r520 is 16pipes is that would be to much of a pain to redesign their r300 architecture to detach the ROP's and add more fragment pipelines. Just going with straight pipelines and add more ALU power per pipeline instead and the higher clockspeed looks to be the more easier way for them.

 

I don't think its much of a pain, at least no more or less so than changing other elements of the pipelines. Its been proven that "deep" ALU pipelines are not really the way to go, but wide ones are, so whatever happens, eventually you'll be looking at processing more pixels in the ALU's at some points of the pipeline than you will have the capability to actually output (although, not necessarily with R520).

 

http://www.beyond3d.com/forum/viewtopic.php?p=483000#483000

Jawed

 

Well they would've had plenty of time to rethink that strategy since the NV40 debuted. I don't think designing your products around your competitor's mistakes is a good approach.

 

At about the time NV40 debuted, R520's functional design was about finished, I expect. I can't imagine ATI has done much to R520 in response to NV40 - that's why I'm pessimistic about FP blending, even if it's a part of Xenos.

Jawed

 

16-1-3-1 (4 blocks) Close to 700mhz..

That still about summs it up.