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 along with 64 TAUs and 48 ROPs.
Compare those specs to the Radeon HD 6990, which comes with clock speeds of 830 MHz on the GPU, and 1250 MHz on the 2048 MB of GDDR5 memory. It features 1536 SPUs as well as 96 Texture Address Units and 32 ROPs.
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 greater data rate. (explain)
Texel RateThe Radeon HD 6990 should be a lot (approximately 105%) better at AF than the GeForce GTX 590. (explain)
Pixel RateThe GeForce GTX 590 will be just a bit (approximately 10%) better at anti-aliasing than the Radeon HD 6990, and capable of handling higher 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: Bandwidth is the max amount of information (counted in megabytes per second) that can be transferred over the external memory interface in one second. It is calculated by multiplying the card's interface width by the speed of its memory. In the case of DDR RAM, it must be multiplied by 2 once again. If DDR5, multiply by 4 instead. The higher 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 texture map elements (texels) that are processed in one second. This number is worked out by multiplying the total texture units 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 processed in one second.
Pixel Rate: Pixel rate is the maximum number of pixels the graphics card can possibly record to the local memory per 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 drawing the pixels (image) on the screen. The actual pixel fill rate also depends on lots of other factors, most notably the memory bandwidth of the card - the lower the memory bandwidth is, the lower the ability to get to the max fill rate.