RSX (PS3GPU) & Xenos (360GPU)

Alright let’s get underway the GPU inside the PS3 is NV47 based which is another name for the 7800GTX. It has 24 pixel shader pipelines and 8 vertex shader pipelines. It’s capable of 136 shader operations per clock and according to Sony it has 256MB of GDDR3 memory at 700MHZ and performs 74.8 billion shader operations per second. Sony also said it’s capable of 1.8 teraflops, which I can tell everyone right now with 100% confidence isn’t true (numbers game) I’m not entirely sure of all the little tricks they used to arrive at such an extreme flops number, but rest assured it isn’t a type of a performance this GPU will ever really achieve. PC videocards such as the X1900XTX have far more raw horsepower than either of the 2 videocards in either console and is pushing a GPU clock speed of up to 650MHZ (some have shipped at 675MHZ) along with 24 more pixel shader pipelines and yet the X1900XTX is just over 500GFLOPS so to even begin entertaining the thought that a less advanced GPU with significantly less raw power could brute force 1.3 teraflops better performance is wishful thinking, but there is no cause to be angry at Sony in this case as they are entitled to market their product regardless of how they choose to do it. As long as they avoid disturbingly untrue statements about the competition its all fair game as far as I’m concerned)

I’m sure some people are wondering how Sony came to the conclusion that the RSX does 136 shader operations per clock or even 74.8 billion shader ops per second? Easy

# The RSX has 24 pixel pipes (each of which performs 5.7 ops) 5.7ops *24 Pixel Pipelines=136.8 shader ops per clock.

# The RSX is clocked at 550MHZ *136 shader ops per clock =74800 (or 74,800,000,000)

There is talk and even an event which took place in Japan in which Sony attended claiming that the RSX will no longer be 550MHZ and it will instead be clocked at 500MHZ and the 256MB of GDDR3 will now be @650MHZ instead of 700. Now there is a lot pointing to this being true, but Sony still hasn’t officially come out and admitted so I’m not sure what to think, but this is a perfect opportunity to see if we learned how to calculate this stuff.

If the RSX is clocked at 500MHZ*136 shader ops per clock that would make the new shader operations per second for the RSX 68 billion instead of the original 74.8 billion weakening the GPU’s performance, but I guess we wont truly find out till the PS3 releases because if anyone has noticed Sony has never posted the RSX clockspeed on the official ps3 site nor did they re-iterate the RSX clockspeed at E3 06. The RSX has 20.8GB/s of video memory bandwidth from the GDDR3 ram. The RSX has an extra 32 GB/sec writing to the system's main memory. If the RSX can fully utilize the memory system it can achieve pushing out 58.2GB/s worth of pixel rendering to memory. The RSX is pretty much a 7800GTX class GPU in some cases its worse in some cases better, nothing that is really new. Now the same can’t be said about the 360’s GPU at all.