Compare any two graphics cards:
GeForce GTX 590 vs Radeon HD 6990
IntroThe GeForce GTX 590 features a clock speed of 607 MHz and a GDDR5 memory speed of 855 MHz. It also features a 384-bit bus, and uses a 40 nm design. It features 512 SPUs, 64 TAUs, and 48 ROPs.
Compare those specifications to the Radeon HD 6990, which makes use of a 40 nm design. AMD has clocked the core frequency at 830 MHz. The GDDR5 RAM runs at a speed of 1250 MHz on this card. It features 1536 SPUs along with 96 Texture Address Units and 32 Rasterization Operator Units.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
As far as performance goes, the GeForce GTX 590 should theoretically be a little bit superior to the Radeon HD 6990 overall. (explain)
Texel RateThe Radeon HD 6990 should be much (about 105%) more effective at texture filtering than the GeForce GTX 590. (explain)
Pixel RateIf using a high screen resolution is important to you, then the GeForce GTX 590 is the winner, but not 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.
GeForce GTX 590
Radeon HD 6990
Memory Bandwidth: Memory bandwidth is the max amount of information (in units of megabytes per second) that can be transported over the external memory interface in a second. It is calculated by multiplying the card's bus width by its memory clock speed. If it uses DDR RAM, the result should be multiplied by 2 once again. If DDR5, multiply by ANOTHER 2x. The better the card's memory bandwidth, the better the card will be in general. It especially helps with anti-aliasing, HDR and high resolutions.
Texel Rate: Texel rate is the maximum number of texture map elements (texels) that are processed per second. This figure is worked out by multiplying the total number of 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 processed per second.
Pixel Rate: Pixel rate is the maximum amount of pixels the video card could possibly record to its local memory in a second - measured in millions of pixels per second. Pixel rate is worked out by multiplying the amount of Raster Operations Pipelines by the the core speed of the card. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel output rate is also dependant on quite a few other factors, most notably the memory bandwidth - the lower the bandwidth is, the lower the ability to reach the max fill rate.
GeForce GTX 590
Radeon HD 6990