So the GDC PS3 dev kits have GF7900's, but will have a GF7600 in the final PS3???

The numbers in NVIDIA slide was included the nrm_pp ops in ALU1 and the scalar op in ALU2, RSX can do same just as the G71. but plz notice, the nrm_pp is a fp16 ops and the scalar ops is unknow , sometmes i think they more like the fixed function , so i have not include the nrm_pp and "scalar" .

the nrm_pp has a 9flops, and the scalar unit in ALU2 may have 2 flops ability . then you can have: 24 * (2*4D FMADD + 1 nrm_pp + 1 scalar) = 2 * (2*8+9+2) = 648 flops /cycle for pixel shader (but i think the meaning of 648flops/cycle number is much less than the 384 flops/cycle).

and for the Vertex Shader, RSX is same to the G71, so you can get 8VS*(1*4D MAD+1*scalar), then that is 80flops/cycle for the RSX vertex shader .

 

your notice is for Vertex Shader not for the Pixel Shader that i had said .

plz check it again.

 

my mistake

 

AFAIR, pixel shaders run at 430MHz; it's the vertex shaders that are clocked at 470MHz.

 

The weird issue brought up is the two different flop numbers, although they come from two different slide presentation which makes things unclear.

The nVidia G70 cleary states a much higher FLOP per clock rate than the Sony RSX slide.

The RSX has half the G70 FLOP rate or not? It's a very odd that by refrencing the G70 chart for vertex and pixel shader FLOP rate, that you get exactly 384 FLOPS with 6 vertex shader and 12 pixel shaders.

Half seems to be a theme with RSX

RSX = half the bus size and bandwidth (128 bit) of a G70
RSX = half the Pixel shaders???? of a G70

Just to note a 7600 GT has 5 Vertex Pipes and 12 Pixel pipes with 8 ROPS and a 560 Mhz core clock.

Of course you'd also get

RSX = Half the heat
RSX = Half the power consumtion
RSX = Half the cost


Looking at these charts showing power efficentcy...the 7600 GT is the leader. To me sort of makes sense for a small console.







I don't know whats true, but I can see why a person could conclude that the RSX is a 7600.

 

Check out the power consumption at load between the 7600GT and 7900GT.

 

Another thing if the RSX is a 7600 GT, they could FAB a lot more of them quicker because the die size is much smaller. This would make it easier to flood the market with PS3's obvioiusly.

 

Do any of these things actually scale linearly? I don't wish to sound facetious but are you just running with this because you made a sound bite "Half seems to be a theme with RSX", instead of any factual reasoning behind it? It was already stated earlier in the thread that RSX was listed as 24 texture lookups/clock which strongly indicates 24 Pixel Shaders.

Not just any person. This 'analysis' in the OP is copy/pasted from a post by Deadmeat.

300 million transistors. If you want to go down the creative theory road, please try to stay within the boundaries of information that has been presented publically.

 

I don't get it, where has this whole 7600 issue come from?

Maybe I've missed something, but I don't recall anything that we've seen to suggest it has anything but 24pixel shaders and 8 vertex shaders (although the vertex shader count is a bit more mysterious, but I haven't seen anything to suggest it wouldn't just be 8). ROPs are the only thing that seem like they would be cut, just because 16 is likely overkill.

 

All comes with the territory of the most popular brand on the market.
But I'd take this as a good sign - PS3 is already living up to the playstation name - it reminds me of how various forums 'deduced' PS2 had 300MPixel/s bilinear fillrate just months before launch

 

Deadmeat and his loyal followers.

 

Deadmeat posted this on Rei-Rom.com




GF7800GTX : 280 shader operations per clock
RSX : 136 shader operations per clock.



At this point I'm leaning towards RSX = 7600 GT tweaked to work with CELL.

The numbers comparing match up by half.
The thermal charateristics of the 7600GT are more console friendly.

 

the E3 RSX slide was also considered the FP32 pixel shader main ALU1/ALU2 only.

the RSX has VS and PS, if you consider the VS ALUs, the PS FP32 ALUs and the nrm_pp, the scalar, than you can get 40 ops for VS and 240 ops for PS too.

 

The pic you posted about the G70 also shows 136 shader instructions per clock... perhaps they just worded it differently for E3 and instead meant instructions rather than ops.

 

I tend to side with Brimstone (and Deadmeat) on this issue for now.
even if that (7600 GT) is not the EXACT story.

I lean towards believing that RSX is significantly cut down from NV47 aka G70 in some areas. RSX is based on NV47. RSX does not = NV47.

what about 12 pixel shaders with double the amount of texture, thus, the 24 textures of RSX ?

Nvidia said that the NV4X is highly re-configurable.

audio, Graphics Synthesizer instructions, and other pieces intergated into RSX could explain the transistor count being similar to G70.

bandwidth-wise, you're not going to support all of the processing elements (pipes, shaders, ROPs, etc) that G70 has on a 128-bit bus, and with no EDRAM.

 

Why Put A GPU in the final system that cant keep up with what they have in the old Evaluation dev kits

Everything outside of the CPU in PS3 = Thrown Together Crap

http://pc.watch.impress.co.jp/docs/2005/0722/kaigai02l.gif

 

But why cripple it into RSX (G7xFUSNY)? I think most newer games tend towards being pixel shader ALU limited, not Texture limited with the X1600 and X1900 both supporting that .So why cripple everything by removing half the shader units? Why not remove half of the TMUs or ROPs, both of which are probably far better candidates if you want to save external bandwidth. And the ROPs should be considerably easier to do that with than the texture units.

 

Here's the deal though - and I do remember that Nvidia slide - but how in the world would a tweaked 7600GT jive with the 300+ million transistor count given by NVidia, also from that same time-frame? There's something going on here, and it's more than just ascribing RSX to one NVidia chip or another - if anything it's not a 7600GT.

On precedent alone going from a chip in PS2 that debuted at 279mm^2 to one in PS3 that is... what, 127mm^2 if G73-based? That's just plain crazy.

Plus the notion of shipping a final GPU that is for all intents and purposes in fact weaker than the setup used in even the original dev kits... I mean, what the hell.

 

it is NOT a new story that use the gpu to do audio, there were some audio preocessing project done on the nv4x already .

http://www.tomshardware.com/hardnews/20040902_135943.html
http://www.nforcershq.com/article1853.html
http://www.bionicfx.com/info.html

http://www-sop.inria.fr/reves/projects/GPUAudio/

 

As I said, I don't believe RSX = G73 - GeForce 7600 GT, but I also don't believe RSX is going to be on par with G70 or G71.

something very significant has changed, if those flops per cycle figures are for real.