Compare any two graphics cards:
GeForce 8500 GT vs GeForce 8600 GT 256MB DDR2
IntroThe GeForce 8500 GT has a GPU core clock speed of 450 MHz, and the 512 MB of DDR2 memory is set to run at 400 MHz through a 128-bit bus. It also is comprised of 16 SPUs, 8 TAUs, and 4 ROPs.
Compare that to the GeForce 8600 GT 256MB DDR2, which makes use of a 80 nm design. nVidia has set the core speed at 540 MHz. The DDR2 memory is set to run at a speed of 400 MHz on this specific card. It features 32 SPUs along with 16 Texture Address Units and 8 ROPs.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Both cards have exactly the same bandwidth, so theoretically they should have the same performance. (explain)
Texel RateThe GeForce 8600 GT 256MB DDR2 will be quite a bit (approximately 140%) more effective at AF than the GeForce 8500 GT. (explain)
Pixel RateIf running with lots of anti-aliasing is important to you, then the GeForce 8600 GT 256MB DDR2 is the winner, by a large margin. (explain)
Please note that the above 'benchmarks' are all just theoretical - the results were calculated based on the card's specifications, and real-world performance may (and probably will) vary at least a bit.
Please note that the price comparisons are based on search keywords - sometimes it might show cards with very similar names that are not exactly the same as the one chosen in the comparison. We do try to filter out the wrong results as best we can, though.
Memory Bandwidth: Memory bandwidth is the largest amount of information (in units of megabytes per second) that can be moved past the external memory interface in one second. It's worked out by multiplying the card's interface width by the speed of its memory. If the card has DDR memory, it must be multiplied by 2 again. If DDR5, multiply by ANOTHER 2x. The better the bandwidth is, the faster the card will be in general. It especially helps with anti-aliasing, HDR and high resolutions.
Texel Rate: Texel rate is the maximum amount of texture map elements (texels) that are applied in one second. This is worked out by multiplying the total texture units of the card by the core clock speed of the chip. The higher this number, the better the graphics card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels processed in a second.
Pixel Rate: Pixel rate is the maximum number of pixels that the graphics card could possibly write to its local memory in a second - measured in millions of pixels per second. Pixel rate is calculated by multiplying the amount of ROPs by the the core speed of the card. ROPs (Raster Operations Pipelines - sometimes also referred to as Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel rate is also dependant on many other factors, most notably the memory bandwidth - the lower the memory bandwidth is, the lower the ability to get to the maximum fill rate.