Compare any two graphics cards:
GeForce GTX 590 vs Radeon HD 6990
IntroThe GeForce GTX 590 uses a 40 nm design. nVidia has set the core speed at 607 MHz. The GDDR5 RAM is set to run at a speed of 855 MHz on this specific card. It features 512 SPUs along with 64 TAUs and 48 Rasterization Operator Units.
Compare all that to the Radeon HD 6990, which comes with GPU 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 SPUs, 96 TAUs, and 32 ROPs.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
The GeForce GTX 590 should theoretically perform a small bit faster than the Radeon HD 6990 in general. (explain)
Texel RateThe Radeon HD 6990 will be much (approximately 105%) faster with regards to texture filtering than the GeForce GTX 590. (explain)
Pixel RateIf using lots of anti-aliasing is important to you, then the GeForce GTX 590 is superior to the Radeon HD 6990, 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: Bandwidth is the max amount of data (counted in MB per second) that can be moved over the external memory interface in a second. It is worked out by multiplying the card's bus width by its memory speed. If the card has DDR memory, it must be multiplied by 2 again. If DDR5, multiply by ANOTHER 2x. The better the card's 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 per second. This figure 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 graphics card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels applied in a second.
Pixel Rate: Pixel rate is the maximum amount of pixels the graphics card can possibly write to its local memory in one second - measured in millions of pixels per second. Pixel rate is calculated by multiplying the number of ROPs by the the card's clock speed. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel fill rate is also dependant on quite a few other factors, most notably the memory bandwidth of the card - the lower the memory bandwidth is, the lower the potential to get to the max fill rate.