Compare any two graphics cards:
GeForce GTX 590 vs Radeon HD 6990
IntroThe GeForce GTX 590 comes with clock 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 Rasterization Operator Units.
Compare all of that to the Radeon HD 6990, which features a core clock speed of 830 MHz and a GDDR5 memory frequency of 1250 MHz. It also features a 256-bit memory bus, and uses a 40 nm design. It is made up of 1536 SPUs, 96 Texture Address Units, and 32 ROPs.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
As far as performance goes, the GeForce GTX 590 should theoretically be a bit superior to the Radeon HD 6990 in general. (explain)
Texel RateThe Radeon HD 6990 is quite a bit (approximately 105%) faster with regards to texture filtering than the GeForce GTX 590. (explain)
Pixel RateThe GeForce GTX 590 will be a bit (approximately 10%) faster with regards to anti-aliasing than the Radeon HD 6990, and should be able to handle higher resolutions while still performing well. (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 largest amount of data (measured in megabytes per second) that can be moved across the external memory interface in one second. It is worked out by multiplying the card's interface width by the speed of its memory. If the card has DDR type RAM, it should be multiplied by 2 again. If it uses DDR5, multiply by 4 instead. The higher the bandwidth is, the better the card will be in general. It especially helps with anti-aliasing, HDR and higher screen resolutions.
Texel Rate: Texel rate is the maximum texture map elements (texels) that can be processed per second. This number is calculated by multiplying the total amount of texture units of the card by the core speed of the chip. The better this number, the better the card will be at 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 that the graphics chip could possibly record to the local memory in a second - measured in millions of pixels per second. The figure is worked out by multiplying the number of Raster Operations Pipelines by the the card's clock speed. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel output rate also depends on quite a few other factors, especially the memory bandwidth - the lower the memory bandwidth is, the lower the potential to reach the max fill rate.