Compare any two graphics cards:
GeForce 9800 GT 512MB vs Radeon HD 6750 1GB
IntroThe GeForce 9800 GT 512MB comes with a GPU core speed of 600 MHz, and the 512 MB of GDDR3 RAM is set to run at 900 MHz through a 256-bit bus. It also features 112 SPUs, 56 TAUs, and 16 ROPs.
Compare all that to the Radeon HD 6750 1GB, which comes with GPU clock speed of 725 MHz, and 1024 MB of GDDR5 memory running at 1000 MHz through a 128-bit bus. It also is made up of 720 SPUs, 36 TAUs, and 16 Raster Operation Units.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
The Radeon HD 6750 1GB should in theory perform just a bit faster than the GeForce 9800 GT 512MB in general. (explain)
Texel RateThe GeForce 9800 GT 512MB is much (approximately 29%) better at texture filtering than the Radeon HD 6750 1GB. (explain)
Pixel RateIf running with a high screen resolution is important to you, then the Radeon HD 6750 1GB is superior to the GeForce 9800 GT 512MB, and very much so. (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: Memory bandwidth is the maximum amount of information (measured in MB per second) that can be moved across the external memory interface within a second. It's worked out by multiplying the card's bus width by the speed of its memory. If it uses DDR type RAM, it should be multiplied by 2 once again. If it uses DDR5, multiply by 4 instead. The better the memory bandwidth, the faster the card will be in general. It especially helps with anti-aliasing, HDR and higher screen resolutions.
Texel Rate: Texel rate is the maximum number of texture map elements (texels) that are applied per second. This is calculated by multiplying the total number of texture units by the core speed of the chip. The higher this number, the better the video card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels processed per second.
Pixel Rate: Pixel rate is the maximum amount of pixels that the graphics chip can possibly write to its local memory in a second - measured in millions of pixels per second. Pixel rate is worked out by multiplying the number of ROPs by the the card's clock speed. 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 also depends 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.