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 runs at a frequency of 855 MHz on this specific model. It features 512 SPUs as well as 64 TAUs and 48 Rasterization Operator Units.
Compare all that to the Radeon HD 6990, which has a clock speed of 830 MHz and a GDDR5 memory frequency of 1250 MHz. It also makes use of a 256-bit memory bus, and makes use of a 40 nm design. It is made up of 1536 SPUs, 96 TAUs, and 32 ROPs.
(No game benchmarks for this combination yet.)
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
In theory, the GeForce GTX 590 should be just a bit faster than the Radeon HD 6990 overall. (explain)
Texel RateThe Radeon HD 6990 should be quite a bit (approximately 105%) better at AF than the GeForce GTX 590. (explain)
Pixel RateIf using a high resolution is important to you, then the GeForce GTX 590 is the winner, but only just. (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 maximum amount of data (counted in megabytes per second) that can be transported past the external memory interface in a second. It is calculated by multiplying the interface width by the speed of its memory. If the card has DDR memory, it 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 AA, HDR and higher screen resolutions.
Texel Rate: Texel rate is the maximum number of texture map elements (texels) that can be applied per second. This figure 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 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 most pixels the video 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 Raster Operations Pipelines by the the card's clock speed. ROPs (Raster Operations Pipelines - aka 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, especially the memory bandwidth of the card - the lower the bandwidth is, the lower the ability to reach the maximum fill rate.