Compare any two graphics cards:
GeForce GTX 280 vs Radeon HD 7950
IntroThe GeForce GTX 280 features a clock frequency of 602 MHz and a GDDR3 memory speed of 1107 MHz. It also features a 512-bit memory bus, and uses a 65 nm design. It is made up of 240 SPUs, 80 TAUs, and 32 Raster Operation Units.
Compare all that to the Radeon HD 7950, which features GPU clock speed of 800 MHz, and 1536 MB of GDDR5 RAM running at 1250 MHz through a 384-bit bus. It also is made up of 1792 SPUs, 112 TAUs, and 32 ROPs.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
As far as performance goes, the Radeon HD 7950 should theoretically be quite a bit superior to the GeForce GTX 280 overall. (explain)
Texel RateThe Radeon HD 7950 is much (approximately 86%) better at anisotropic filtering than the GeForce GTX 280. (explain)
Pixel RateIf using lots of anti-aliasing is important to you, then the Radeon HD 7950 is superior to the GeForce GTX 280, by far. (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 max amount of data (counted in megabytes per second) that can be transported over the external memory interface in one second. It's worked out by multiplying the card's bus width by its memory clock speed. In the case of DDR type RAM, it should be multiplied by 2 once again. If it uses DDR5, multiply by 4 instead. The higher the card's 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 texture map elements (texels) that can be processed per second. This is calculated by multiplying the total texture units by the core clock speed of the chip. The better this number, 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 most pixels the video card can possibly record to its local memory per second - measured in millions of pixels per second. Pixel rate is calculated by multiplying the amount of colour 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 fill rate is also dependant on lots of other factors, most notably the memory bandwidth - the lower the bandwidth is, the lower the ability to reach the maximum fill rate.