Compare any two graphics cards:
GeForce GTX 580 3GB vs Radeon HD 5970
IntroThe GeForce GTX 580 3GB has clock speeds of 772 MHz on the GPU, and 1002 MHz on the 3072 MB of GDDR5 memory. It features 512 SPUs along with 64 TAUs and 48 Rasterization Operator Units.
Compare all of that to the Radeon HD 5970, which features a GPU core clock speed of 725 MHz, and 1024 MB of GDDR5 RAM running at 1000 MHz through a 256-bit bus. It also is comprised of 1600 SPUs, 160 Texture Address Units, and 64 Raster Operation Units.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
As far as performance goes, the Radeon HD 5970 should in theory be a lot superior to the GeForce GTX 580 3GB in general. (explain)
Texel RateThe Radeon HD 5970 should be a lot (approximately 370%) better at anisotropic filtering than the GeForce GTX 580 3GB. (explain)
Pixel RateThe Radeon HD 5970 should be much (about 150%) faster with regards to full screen anti-aliasing than the GeForce GTX 580 3GB, and also should be able to handle higher screen resolutions without slowing down too much. (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 max amount of data (measured in MB per second) that can be transferred over the external memory interface in a second. The number is worked out by multiplying the bus width by its memory clock speed. If the card has DDR type memory, the result should be multiplied by 2 once again. If it uses DDR5, multiply by 4 instead. The higher the memory bandwidth, the faster the card will be in general. It especially helps with AA, High Dynamic Range and higher screen resolutions.
Texel Rate: Texel rate is the maximum amount of texture map elements (texels) that are applied in one second. This figure is worked out by multiplying the total amount of texture units of the card by the core clock 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 maximum number of pixels that the graphics chip could possibly record to its local memory in one second - measured in millions of pixels per second. The number is calculated by multiplying the amount of ROPs by the the card's clock speed. 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 also depends on lots of other factors, most notably the memory bandwidth - the lower the bandwidth is, the lower the ability to get to the maximum fill rate.