Compare any two graphics cards:
GeForce GTX 580 3GB vs Radeon HD 5970
IntroThe GeForce GTX 580 3GB features a GPU core speed of 772 MHz, and the 3072 MB of GDDR5 RAM is set to run at 1002 MHz through a 384-bit bus. It also is made up of 512 SPUs, 64 Texture Address Units, and 48 Raster Operation Units.
Compare those specs to the Radeon HD 5970, which comes with a core clock speed of 725 MHz and a GDDR5 memory frequency of 1000 MHz. It also makes use of a 256-bit memory bus, and uses a 40 nm design. It is made up of 1600 SPUs, 160 Texture Address Units, and 64 ROPs.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
In theory, the Radeon HD 5970 is 33% quicker than the GeForce GTX 580 3GB in general, due to its greater data rate. (explain)
Texel RateThe Radeon HD 5970 will be a lot (about 370%) more effective at anisotropic filtering than the GeForce GTX 580 3GB. (explain)
Pixel RateIf running with a high resolution is important to you, then the Radeon HD 5970 is the winner, 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.
One or more cards in this comparison are multi-core. This means that their bandwidth, texel and pixel rates are theoretically doubled - this does not mean the card will actually perform twice as fast, but only that it should in theory be able to. Actual game benchmarks will give a more accurate idea of what it's capable of.
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 max amount of information (measured in MB per second) that can be transferred past the external memory interface in a second. It is worked out by multiplying the card's bus width by its memory clock speed. If it uses DDR RAM, 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 number of texture map elements (texels) that are processed in one second. This number is worked out by multiplying the total texture units of the card by the core speed of the chip. The better this number, the better the graphics card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels processed per second.
Pixel Rate: Pixel rate is the most pixels the video card could possibly record to the local memory per 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 - also called Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel rate is also dependant on quite a few other factors, most notably the memory bandwidth of the card - the lower the bandwidth is, the lower the ability to get to the max fill rate.