
Originally Posted by
scaryjim
That's to do with the different way the two cards work to acheive the same result. Basically, both cards have a "core" processor and "shaders" - the core decides what needs doing, and the shaders do the grunt work of generating, colouring and shading the pixels. NVidia run their core and shaders at different speeds, so while ATI run everything at the same speed. To complicate matters, NVidia's shaders also do more calculations than ATIs, so NVidia cards have far less shaders than ATI cards (the 9800GT has 128, while the 5670 has 400!). The same applies to memory - the NVidia card uses a wider memory path, so while the memory runs at a slower clock speed it moves more data with each transfer.
The only way to actually compare the performance of two cards using such different approaches is to benchmark them running a variety of applications.