Compare any two graphics cards:
GeForce GTX 590 vs Radeon HD 6990
IntroThe GeForce GTX 590 comes with core speeds of 607 MHz on the GPU, and 855 MHz on the 1536 MB of GDDR5 RAM. It features 512 SPUs as well as 64 Texture Address Units and 48 ROPs.
Compare those specifications to the Radeon HD 6990, which has a GPU core clock speed of 830 MHz, and 2048 MB of GDDR5 RAM running at 1250 MHz through a 256-bit bus. It also is made up of 1536 Stream Processors, 96 Texture Address Units, and 32 Raster Operation Units.
(No game benchmarks for this combination yet.)
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
In theory, the GeForce GTX 590 will be 3% faster than the Radeon HD 6990 overall, because of its higher bandwidth. (explain)
Texel RateThe Radeon HD 6990 should be a lot (more or less 105%) better at AF than the GeForce GTX 590. (explain)
Pixel RateIf running with lots of anti-aliasing is important to you, then the GeForce GTX 590 is the winner, not by a very large margin though. (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 information (counted in MB per second) that can be transferred past the external memory interface in a second. It's worked out by multiplying the interface width by its memory speed. If it uses DDR RAM, 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 anti-aliasing, HDR and higher screen resolutions.
Texel Rate: Texel rate is the maximum number of texture map elements (texels) that can be applied 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 higher the texel rate, the better the video card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels processed in a second.
Pixel Rate: Pixel rate is the most pixels that the graphics card could possibly record to the local memory in a second - measured in millions of pixels per second. The number is worked out by multiplying the number of Raster Operations Pipelines by the the core clock speed. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel output rate is also dependant on lots of other factors, especially the memory bandwidth of the card - the lower the memory bandwidth is, the lower the ability to reach the maximum fill rate.