Compare any two graphics cards:
GeForce 8800 GTS (G80) 640MB vs Radeon HD 4650 1GB
IntroThe GeForce 8800 GTS (G80) 640MB makes use of a 90 nm design. nVidia has clocked the core frequency at 513 MHz. The GDDR3 memory is set to run at a speed of 792 MHz on this model. It features 96 SPUs along with 48 Texture Address Units and 20 Rasterization Operator Units.
Compare those specs to the Radeon HD 4650 1GB, which comes with a clock frequency of 600 MHz and a GDDR3 memory frequency of 700 MHz. It also uses a 128-bit bus, and makes use of a 55 nm design. It is made up of 320(64x5) SPUs, 32 TAUs, and 8 Raster Operation Units.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
In theory, the GeForce 8800 GTS (G80) 640MB should be 183% faster than the Radeon HD 4650 1GB overall, due to its higher bandwidth. (explain)
Texel RateThe GeForce 8800 GTS (G80) 640MB should be much (about 28%) better at texture filtering than the Radeon HD 4650 1GB. (explain)
Pixel RateIf running with a high screen resolution is important to you, then the GeForce 8800 GTS (G80) 640MB 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: Bandwidth is the largest amount of data (measured in MB per second) that can be moved over the external memory interface in one second. It is worked out by multiplying the card's interface width by its memory speed. If the card has DDR RAM, it should be multiplied by 2 once again. If DDR5, multiply by 4 instead. The better the memory bandwidth, the better the card will be in general. It especially helps with AA, HDR and high resolutions.
Texel Rate: Texel rate is the maximum number of texture map elements (texels) that can be processed in one second. This number is calculated by multiplying the total number of texture units 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 the video card can possibly record to its local memory in a second - measured in millions of pixels per second. The figure is calculated by multiplying the number of ROPs by the the core clock speed. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel fill rate is also dependant on many other factors, especially the memory bandwidth of the card - the lower the memory bandwidth is, the lower the potential to reach the maximum fill rate.