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

[mozmo]

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.

Well all of the dev kits so far have included a desktop graphics part with double the memory bandwidth and double the effective fillrate/AA performance. I think just having a card in there lets developers start coding for a G70 based architecture. It happended with the 360 too, developers had problems with the dual G5 cores performing better than the final xcpu and had to retweak code to get stuff running well. Same goes with the video cards used, they had double the ROPS of the final xenos.

Until final RSX kits are out there with final clocks we won't really know what developers will achieve, for the time being a lot of what we see has been all pc graphic card based tech demos. Probably also explains the heavy amount of tech demos, developers don't wish to developer too much of their engines when they know they'll need to rework stuff for the final config.

 

[Carl B]

Nvidia has essentially gone on record before as saying that RSX would be more powerful than a 7800GTX. Now, I don't put much effort into analyzing PR feints, so this does not matter to me in and of itself. But still, the shader op numbers on that slide aside, that same presentation introduced RSX as a 300+ million tran chip. The 7600 is nearly half of that. I don't think those shader ops numbers are telling us the whole story, unless NVidia has conspired to actually torpedo the PS3 by providing an architecture with a performance to transistor ratio far far worse than their own PC architectures of over a year ago. And I think we all know whatever the RSX is or is not, it most certainly cannot be that.

Unless RSX is now also less than 300 million transistors strong, there is a lot more here than meets the eye; like 123 million transistors more.

 

[ihamoitc2005]

Efficient

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.

7800 & 7900 has much more performance/watts so 7600 is less effiicient.

 

[Carl B]

Well all of the dev kits so far have included a desktop graphics part with double the memory bandwidth and double the effective fillrate/AA performance. I think just having a card in there lets developers start coding for a G70 based architecture. It happended with the 360 too, developers had problems with the dual G5 cores performing better than the final xcpu and had to retweak code to get stuff running well. Same goes with the video cards used, they had double the ROPS of the final xenos.

Until final RSX kits are out there with final clocks we won't really know what developers will achieve, for the time being a lot of what we see has been all pc graphic card based tech demos. Probably also explains the heavy amount of tech demos, developers don't wish to developer too much of their engines when they know they'll need to rework stuff for the final config.

Well, that would just be ridiculous on Sony's part, I have to say. Which is why I don't buy it for a second. Why not put a 6600GT in there instead then? Certainly not a 7800GTX or the 6800's in SLI. Microsoft changed the scene from out of order to in-order with the move to XeCPU equipped dev kits; but they had no choice!!! They simply had to make due with using readily attainable Power-compliant dev kits.

The entire idea of the use of the NVidia chips to this point has been because they are essentially the same architecture as the RSX; but you don't put your developers in a situation where they in fact ultimately have to dumb things down if you can help it. It would have been easy enough to provide PS3 devs with an environment where the RSX would in fact present an upgrade - this would have been easy.

So... anyway I'm inclined to think that comparing the RSX to a 7600GT is probably not the best comparison to make.

 

[Megadrive1988]

Nvidia has essentially gone on record before as saying that RSX would be more powerful than a 7800GTX. Now, I don't put much effort into analyzing PR feints, so this does not matter to me in and of itself. But still, the shader op numbers on that slide aside, that same presentation introduced RSX as a 300+ million tran chip. The 7600 is nearly half of that. I don't think those shader ops numbers are telling us the whole story, unless NVidia has conspired to actually torpedo the PS3 by providing an architecture with a performance to transistor ratio far far worse than their own PC architectures of over a year ago. And I think we all know whatever the RSX is or is not, it most certainly cannot be that.

Unless RSX is now also less than 300 million transistors strong, there is a lot more here than meets the eye; like 123 million transistors more.

the 550 MHz RSX could be more powerful than 430 MHz 7800 GTX in total amount of textures

perhaps they cut out half the pixel shaders, but each pixel shader now has 2 textures instead of 1.

or maybe RSX is a totally different arrangement of functional blocks, but still based on all of the NV47 technologies.

Is RSX also the northbridge of PS3 or is that Cell ?

the RSX GPU core could be to G73 what the NV2A was to NV20. not the perfect analogy, I'm just grasping at straws here.

all we do know is RSX gets/has about half the bandwidth (to GDDR3) of the highend G70 and G71.

*something* has got to go, and probably more than just 8 ROPs.

we'll see.

 

[mckmas8808]

Probably also explains the heavy amount of tech demos, developers don't wish to developer too much of their engines when they know they'll need to rework stuff for the final config.

Okay come on man. I can see where you are going with this. Those demos were stripped from REAL GAMES. Stop making this what it's not.

 

[scooby_dooby]

Nvidia has essentially gone on record before as saying that RSX would be more powerful than a 7800GTX.

I hope you're not referring to the PSM quote that it was 'faster' cause that could simply be clockspeed if taken literally.

 

[Carl B]

the 550 MHz RSX could be more powerful than 430 MHz 7800 GTX in total amount of textures

perhaps they cut out half the pixel shaders, but each pixel shader now has 2 textures instead of 1.

or maybe RSX is a totally different arrangement of functional blocks, but still based on all of the NV47 technologies.

Is RSX also the northbridge of PS3 or is that Cell ?

the RSX GPU core could be to G73 what the NV2A was to NV20. not the perfect analogy, I'm just grasping at straws here.

all we do know is RSX gets/has about half the bandwidth (to GDDR3) of the highend G70 and G71.

*something* has got to go, and probably more than just 8 ROPs.

we'll see.

I don't dispute the ROPs theory at all - even more reason to wonder what comprises the rest of those transistors though in that 300 million.

Unlike the XBox architectures also, the RSX is indeed not the northbridge.

Certainly I don't pretend I know what the RSX is, I just have to say "no" though to the idea of a tweaked 177 million tran chip being it. There may in the end be a lot in common between the two, but with that kind of transistor spread, there's obviously a lot going to be very very different as well.

 

[Bad_Boy]

I hope you're not referring to the PSM quote that it was 'faster' cause that could simply be clockspeed if taken literally.

http://www.nforcershq.com/article3417.html
http://www.bit-tech.net/bits/2005/07/11/nvidia_rsx_interview/2.html

bit-tech.net chats with NVIDIA's David Kirk and discusses upcoming NVIDIA technology, the G70, PS3 RSX - and what the future holds for PC gamers:

The graphics processor in the PlayStation 3 is NVIDIA-designed and is called RSX. How does it compare next to the 7800? "The two products share the same heritage, the same technology. But RSX is faster," said Kirk.

take that as whatever youd like.

 

[Farid]

For what it worth...

The RSX is not a G73, nor it have the same Quads configuration as G73.

No need to speculate about that any further, really.

 

[Megadrive1988]

I don't dispute the ROPs theory at all - even more reason to wonder what comprises the rest of those transistors though in that 300 million.

Unlike the XBox architectures also, the RSX is indeed not the northbridge.

Certainly I don't pretend I know what the RSX is, I just have to say "no" though to the idea of a tweaked 177 million tran chip being it. There may in the end be a lot in common between the two, but with that kind of transistor spread, there's obviously a lot going to be very very different as well.

well, RSX is going to have FAR more texture performance than 7600 GT, and alot of other things that 7600 GT does not have.

As I said, I don't think RSX is G73 at all. but it sure as heck is not a G70 or G71.

 

[Brimstone]

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.

At this point all I can see is the logic in concluding a 7600 level GPU by just comparing the paticular slides. The math of dividing things in half (more or less) from the G70 slide and things start to match up. The arithmetic is pretty basic. The PS3 slides could be refering to totally different stuff, making the comparisons irrelivant. But it's one hell of coincidence how the numbers logically dovetail without any hocus pocus fuzzy math.

I was thinking maybe Sony lowballed the intial RSX spec to give a marketing boost at a later date by releasing a doubled spec which would equal a G70. Everyone would think, "Oh my god they doubled the power of the RSX", when in reality the intial RSX specs were that of a 7600 GeForce. So maybe a G70 is in and this is a marketing stunt. Time will tell.

 

[Carl B]

Well, it's 300 million transistors of something is all I'm saying.

G73 is, almost literally, half of that.

 

[Bobbler]

I'm guessing this thread is either funny or frustrating depending on which dev you ask...

Generally it's a safe bet to bet against deadmeat and pals on things. How many times has he actually been right on things? I'm actually kind of surprised some of you long time members are so openly believing him, and quoting something from rei-rom or opa or any site like that is generally not a good way to be taken seriously.

 

[mckmas8808]

I'm guessing this thread is either funny or frustrating depending on which dev you ask...

Generally it's a safe bet to bet against deadmeat and pals on things. How many times has he actually been right on things? I'm actually kind of surprised some of you long time members are so openly believing him, and quoting something from rei-rom or opa or any site like that is generally not a good way to be taken seriously.

You know seriously, I starting to wonder the samething. Isn't rei-rom known for being a troll forum? What's really good?