Compare any two graphics cards:
GeForce 8800 GTS (G92) vs GeForce 9800 GTX
IntroThe GeForce 8800 GTS (G92) features a GPU core speed of 650 MHz, and the 512 MB of GDDR3 memory runs at 970 MHz through a 256-bit bus. It also features 128 SPUs, 64 Texture Address Units, and 16 Raster Operation Units.
Compare all of that to the GeForce 9800 GTX, which uses a 65 nm design. nVidia has clocked the core speed at 675 MHz. The GDDR3 RAM works at a frequency of 1100 MHz on this card. It features 128 SPUs as well as 64 Texture Address Units and 16 ROPs.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
As far as performance goes, the GeForce 9800 GTX should in theory be a little bit superior to the GeForce 8800 GTS (G92) overall. (explain)
Texel RateThe GeForce 9800 GTX will be a bit (approximately 4%) more effective at AF than the GeForce 8800 GTS (G92). (explain)
Pixel RateThe GeForce 9800 GTX should be a little bit (approximately 4%) more effective at AA than the GeForce 8800 GTS (G92), and able to handle higher resolutions without slowing down too much. (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.
Memory Bandwidth: Bandwidth is the max amount of data (counted in MB per second) that can be transferred over the external memory interface in a second. The number is calculated by multiplying the bus width by its memory speed. In the case of DDR memory, it must be multiplied by 2 again. If it uses DDR5, multiply by 4 instead. The better the bandwidth is, the faster the card will be in general. It especially helps with anti-aliasing, High Dynamic Range and higher screen resolutions.
Texel Rate: Texel rate is the maximum amount of texture map elements (texels) that are applied per second. This is calculated by multiplying the total texture units by the core speed of the chip. The higher this number, the better the card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels in one second.
Pixel Rate: Pixel rate is the maximum amount of pixels the video card could possibly write to the local memory per second - measured in millions of pixels per second. Pixel rate is calculated by multiplying the number of Raster Operations Pipelines by the the card's clock speed. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel output rate also depends on lots of other factors, especially the memory bandwidth of the card - the lower the bandwidth is, the lower the ability to reach the max fill rate.