Compare any two graphics cards:
GeForce GTX 280 vs Radeon HD 7950
IntroThe GeForce GTX 280 features a GPU clock speed of 602 MHz, and the 1024 MB of GDDR3 memory runs at 1107 MHz through a 512-bit bus. It also is made up of 240 SPUs, 80 TAUs, and 32 Raster Operation Units.
Compare those specifications to the Radeon HD 7950, which uses a 28 nm design. AMD has set the core frequency at 800 MHz. The GDDR5 RAM is set to run at a frequency of 1250 MHz on this specific model. It features 1792 SPUs along with 112 Texture Address Units and 32 Rasterization Operator Units.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Theoretically speaking, the Radeon HD 7950 will be 69% quicker than the GeForce GTX 280 in general, due to its greater data rate. (explain)
Texel RateThe Radeon HD 7950 should be quite a bit (about 86%) better at AF than the GeForce GTX 280. (explain)
Pixel RateIf using a high screen resolution is important to you, then the Radeon HD 7950 is superior to the GeForce GTX 280, 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.
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 maximum amount of information (counted in megabytes per second) that can be transferred across the external memory interface in a second. The number is worked out by multiplying the card's interface width by its memory speed. If the card has DDR type memory, it must be multiplied by 2 once again. If it uses DDR5, multiply by 4 instead. The higher 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 can be processed in one second. This is worked out by multiplying the total texture units of the card 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 in a second.
Pixel Rate: Pixel rate is the maximum amount of pixels the graphics card could possibly record to its local memory in a second - measured in millions of pixels per second. Pixel rate is calculated by multiplying the amount of Render Output Units by the the core speed of the card. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel output rate is also dependant on quite a few other factors, most notably the memory bandwidth - the lower the memory bandwidth is, the lower the ability to reach the maximum fill rate.