PS3 gpu 2x more powerful than X360 gpu?
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Jawed
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I agree. That's what I was saying.nAo said:
I just thought I'd spin the numbers around for some entertainment, pointing out that NVidia's technique produces more impressive numbers.
It's fun to come up with some plausible numbers to take the shine off NVidia's wild claims. Hmm, the pixel shaders can do two Dot4's per clock, and a vertex shader should be doing Dot5s, shouldn't it?...
Anyway, my real interest in "shader op" specifications is to see if they can give any clues as to the architecture of the respective GPU. So far we're failing miserably
I don't remember those figures, @36 minutes "100 billion Shader Ops / sec" appears on the slide, followed by "51 billion dot products per sec".
http://www.gamespot.com/live/stream...ath=2stream_sonypress_e305.asx&pid=927750
Jawed
about nv40: vertex shader -> one dot4 per clock cycle, pixel shader -> one dot4 per clock cycle (the second ALU can't do a dot4, just a vec4 mul, AFAIK, according GPU GEMS2 chapter 30..)Jawed said:
In fact I thought nvidia extended the second ALU in each pixel pipeline to perform a dot4 too, but also in this case numbers don't add up.
A 24 pixel pipes and 9 vertex shaders 'extended' NV40 would do 53 dot4 per clock cycle, there are needed other 40 (!!) dot4 products per cycle to reach RSX dot4 figure!
AS you can see even if it's just an improved nv40, it seems RSX, has undergone some non trivial changes.
I could be completely wrong though
Maybe in their dot4 products per cycle number they're adding up TMUs work too :?
Yeah..but at minute 25th you can read:
Code:
Programmable shading processors: 136 shader operations per clock cyclersx
12 vertexpipes -> 24ops
24 pixelpipes -> 96ops using nv40 design as reference
16 texture units -> 16ops
-------------------------------
136ops/cycle
or
8 vertexpipes -> 16ops
24 pixelpipes -> 96ops
24 texture units - 24ops
-----------------------------
136ops/cycle
12 vertexpipes -> 24ops
24 pixelpipes -> 96ops using nv40 design as reference
16 texture units -> 16ops
-------------------------------
136ops/cycle
or
8 vertexpipes -> 16ops
24 pixelpipes -> 96ops
24 texture units - 24ops
-----------------------------
136ops/cycle
Jawed
Legend
Which would imply the major change in RSX/G70 is to separate the texture unit from the first shader ALU.
I suppose the second of those makes most sense.
The issue is that the vertex pipeline should also have texture units, though, shouldn't it?... Presumably there's a texture address to be calculated?...
Jawed
I suppose the second of those makes most sense.
The issue is that the vertex pipeline should also have texture units, though, shouldn't it?... Presumably there's a texture address to be calculated?...
Jawed
Jawed
Legend
Well I predicted last year that the PS3 would have 2.4x more 'flops' than X360 on paper...so not far off if it's only 2x!
I actually think this paper 'flops' comparison is accurate. Why? It simple! 8)
Xbox = Microsoft + nVidia
They marketed the console with 'paper flops' to attain the most imaginitive way to substantiate flops.
X360 = Microsoft + ATI
---> They will try to do the sme IMHO....
PS3 = Sony + nVidia
---> They will try to do the sme IMHO....
So essentially, were comparing APPLES to APPLES! 8)
Total X360 ~ 1 TFLOPS
Total PS3 ~ 2 TFLOPS
Therefore PS3 twice as 'powerful' as X360!
QED
/runs
I actually think this paper 'flops' comparison is accurate. Why? It simple! 8)
Xbox = Microsoft + nVidia
They marketed the console with 'paper flops' to attain the most imaginitive way to substantiate flops.
X360 = Microsoft + ATI
---> They will try to do the sme IMHO....
PS3 = Sony + nVidia
---> They will try to do the sme IMHO....
So essentially, were comparing APPLES to APPLES! 8)
Total X360 ~ 1 TFLOPS
Total PS3 ~ 2 TFLOPS
Therefore PS3 twice as 'powerful' as X360!
QED
/runs
One more question: anyone here thinks that R500 wouldnt surpasse very well a 6800, in 720p(+FPS), but would be harder (to surpasse) 1080i/p 
It isnt that the point, be the best at 720p (the ideal condition for XB360), but very IQ per pixel
I mean having a image as good ( at least ) as RSX but with fewer pixels (lower rez) on the screen.
Because if they (RSX) are only puting 2X more pixels but the same Q, it only interest for the very few with 1080i/p tv. Unless they can make a better imagem at 720p( and no 1080 rez), but I dont think so.
I am expecting to have both the same IQ, but RSX @ higer-rez (that the reason for the almost 2 Tflops figure)
It isnt that the point, be the best at 720p (the ideal condition for XB360), but very IQ per pixel
I mean having a image as good ( at least ) as RSX but with fewer pixels (lower rez) on the screen.
Because if they (RSX) are only puting 2X more pixels but the same Q, it only interest for the very few with 1080i/p tv. Unless they can make a better imagem at 720p( and no 1080 rez), but I dont think so.
I am expecting to have both the same IQ, but RSX @ higer-rez (that the reason for the almost 2 Tflops figure)
1080i and 720p aren't that far apart pixel wise. You must mean 1080p.
I think the jury is still out on who supports 720p better. The "eDRAM" has higher bandwidth, but its smaller, and HDR/AA modes might slow it down. Plus, there is shader rate vs fillrate. Many games are using shadow buffers and stencil shadows not, plus lots of render-to-texture, and that requires lots more fillrate.
I think the jury is still out on who supports 720p better. The "eDRAM" has higher bandwidth, but its smaller, and HDR/AA modes might slow it down. Plus, there is shader rate vs fillrate. Many games are using shadow buffers and stencil shadows not, plus lots of render-to-texture, and that requires lots more fillrate.
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