Compare any two graphics cards:
GeForce GTX 590 vs Radeon HD 6990
IntroThe GeForce GTX 590 features a core clock speed of 607 MHz and a GDDR5 memory frequency of 855 MHz. It also uses a 384-bit bus, and makes use of a 40 nm design. It is made up of 512 SPUs, 64 Texture Address Units, and 48 Raster Operation Units.
Compare those specifications to the Radeon HD 6990, which comes with GPU clock speed of 830 MHz, and 2048 MB of GDDR5 memory running at 1250 MHz through a 256-bit bus. It also is made up of 1536 SPUs, 96 Texture Address Units, and 32 Raster Operation Units.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
The GeForce GTX 590, in theory, should perform a little bit faster than the Radeon HD 6990 overall. (explain)
Texel RateThe Radeon HD 6990 is much (more or less 105%) more effective at texture filtering than the GeForce GTX 590. (explain)
Pixel RateThe GeForce GTX 590 should be just a bit (approximately 10%) better at FSAA than the Radeon HD 6990, and should be capable of handling higher resolutions more effectively. (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 information (in units of megabytes per second) that can be moved over the external memory interface within a second. The number is worked out by multiplying the bus width by the speed of its memory. If the card has DDR memory, it should be multiplied by 2 again. If DDR5, multiply by 4 instead. The higher the memory bandwidth, the faster the card will be in general. It especially helps with anti-aliasing, High Dynamic Range and high resolutions.
Texel Rate: Texel rate is the maximum number of texture map elements (texels) that are processed per second. This number is calculated by multiplying the total texture units of the card by the core speed of the chip. The higher this number, the better the video card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels applied per second.
Pixel Rate: Pixel rate is the most pixels that the graphics card could possibly record to its local memory per second - measured in millions of pixels per second. Pixel rate is worked out by multiplying the amount of ROPs by the the core speed of the card. ROPs (Raster Operations Pipelines - sometimes also referred to as Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel output rate also depends 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 maximum fill rate.