Compare any two graphics cards:
GeForce 9600 GT 512MB vs Radeon HD 3850 512MB
IntroThe GeForce 9600 GT 512MB features a GPU core speed of 650 MHz, and the 512 MB of GDDR3 RAM runs at 900 MHz through a 256-bit bus. It also is made up of 64 Stream Processors, 32 Texture Address Units, and 16 Raster Operation Units.
Compare those specifications to the Radeon HD 3850 512MB, which comes with core speeds of 668 MHz on the GPU, and 828 MHz on the 512 MB of GDDR3 memory. It features 320(64x5) SPUs along with 16 Texture Address Units and 16 Rasterization Operator Units.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
In theory, the GeForce 9600 GT 512MB will be 9% faster than the Radeon HD 3850 512MB overall, due to its greater data rate. (explain)
Texel RateThe GeForce 9600 GT 512MB should be quite a bit (more or less 95%) faster with regards to anisotropic filtering than the Radeon HD 3850 512MB. (explain)
Pixel RateIf using lots of anti-aliasing is important to you, then the Radeon HD 3850 512MB is the winner, but it probably won't make a huge difference. (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 max amount of information (in units of MB per second) that can be transferred across the external memory interface within a second. It is worked out by multiplying the card's bus width by the speed of its memory. If it uses DDR memory, the result should be multiplied by 2 again. If it uses DDR5, multiply by ANOTHER 2x. The better the bandwidth is, the better the card will be in general. It especially helps with anti-aliasing, High Dynamic Range and high resolutions.
Texel Rate: Texel rate is the maximum amount of texture map elements (texels) that are applied per second. This number is calculated by multiplying the total amount of texture units by the core speed of the chip. The better the texel rate, the better the graphics card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels applied per second.
Pixel Rate: Pixel rate is the maximum number of pixels the video card could possibly write to its local memory in one second - measured in millions of pixels per second. Pixel rate is worked out by multiplying the amount of colour ROPs by the the core speed of the card. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel fill rate also depends on many other factors, most notably the memory bandwidth of the card - the lower the bandwidth is, the lower the potential to reach the max fill rate.