Ati vs Nvidia

[nibbler]

So why is nvidia so much better than ATI? Is it anything to do with the shader clock as that seems to affect performance a lot in nvidia GPUs?
Someone suggested to me that nvidia bribe Stanford University which I find so ridiculous that I want a proper answer...

[LuckyNV]

Its to do with the Core software, Nvidia uses CUDA and AMD uses OpenCL, I believe Stanford's OpenCL core is in its infancy and not very well optimised.

There was some comment in the FAH forums about AMD going back on something or scrapping something (language wise) and Stanford had to rewrite a bunch of stuff.

[Golden Dragoon]

It is also down to the shader configuration, ATi's shaders are currently running in groups of 5, with 1 complex one that can do all calculations, and 4 simpler ones that can do most game calculations, yet are not quite so good, or completely incapable of doing some FaH calculations, nVidia uses nothing but complex shaders but fewer of them, and to make up the game performance clocks them much higher than ATi.

Of course some projects can use all of the power of the ATi cards, take a look at MilkyWay@home, no one contributing there would think of using a nVidia card, as they are outclassed in every area by ATi, because the calculations they are running are are DP (double precision) calcs and are able to make use of ATi's much higher DP performance (just a few mins per wu isn't uncommon on the faster cards, so they allow contributers to download several wu's at once to keep them crunching and to try and stop the servers being thrashed constantly).

The new ATi cards should be a lot better at folding as they are changing the 1+4 layout and going for groups of 4, which will all be almost as advanced as the 1 complex shader in the old groupings, they are expected to launch with the 6900 series, even though I want one I couldn't afford it right now so have gone to a GTX 460.