Compare any two graphics cards:
GeForce GTX 580 3GB vs Radeon HD 5970
IntroThe GeForce GTX 580 3GB uses a 40 nm design. nVidia has clocked the core frequency at 772 MHz. The GDDR5 memory is set to run at a frequency of 1002 MHz on this specific model. It features 512 SPUs along with 64 Texture Address Units and 48 Rasterization Operator Units.
Compare those specifications to the Radeon HD 5970, which comes with a clock speed of 725 MHz and a GDDR5 memory frequency of 1000 MHz. It also makes use of a 256-bit bus, and makes use of a 40 nm design. It is comprised of 1600 SPUs, 160 Texture Address Units, and 64 Raster Operation Units.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Theoretically speaking, the Radeon HD 5970 will be 33% faster than the GeForce GTX 580 3GB overall, due to its higher bandwidth. (explain)
Texel RateThe Radeon HD 5970 is a lot (approximately 370%) faster with regards to AF than the GeForce GTX 580 3GB. (explain)
Pixel RateThe Radeon HD 5970 should be a lot (more or less 150%) more effective at full screen anti-aliasing than the GeForce GTX 580 3GB, and also will be capable of handling higher screen resolutions without losing too much performance. (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: Memory bandwidth is the largest amount of data (counted in megabytes per second) that can be transferred over the external memory interface in a second. It is calculated by multiplying the card's interface width by its memory clock speed. If the card has DDR type RAM, it must be multiplied by 2 again. If it uses DDR5, multiply by ANOTHER 2x. The better the memory bandwidth, 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 is worked out by multiplying the total number of texture units of the card by the core clock speed of the chip. The higher the texel rate, the better the card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels in a second.
Pixel Rate: Pixel rate is the maximum number of pixels that the graphics card could possibly write to the local memory in a second - measured in millions of pixels per second. The number is calculated by multiplying the number of Raster Operations Pipelines by the the core speed of the card. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel rate also depends on quite a few other factors, especially the memory bandwidth of the card - the lower the memory bandwidth is, the lower the potential to reach the max fill rate.