Compare any two graphics cards:
GeForce GTX 580 vs Radeon HD 7970
IntroThe GeForce GTX 580 comes with a clock frequency of 772 MHz and a GDDR5 memory frequency of 1002 MHz. It also makes use of a 384-bit bus, and makes use of a 40 nm design. It is comprised of 512 SPUs, 64 TAUs, and 48 Raster Operation Units.
Compare that to the Radeon HD 7970, which makes use of a 28 nm design. AMD has set the core frequency at 925 MHz. The GDDR5 RAM runs at a frequency of 1375 MHz on this specific card. It features 2048 SPUs along with 128 Texture Address Units and 32 ROPs.
(No game benchmarks for this combination yet.)
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Theoretically, the Radeon HD 7970 should perform quite a bit faster than the GeForce GTX 580 in general. (explain)
Texel RateThe Radeon HD 7970 will be much (approximately 140%) more effective at anisotropic filtering than the GeForce GTX 580. (explain)
Pixel RateThe GeForce GTX 580 will be a lot (approximately 25%) better at AA than the Radeon HD 7970, and capable of handling higher screen 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.
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 data (measured in megabytes per second) that can be transported past the external memory interface in one second. It is calculated by multiplying the card's interface width by its memory clock speed. In the case of DDR type memory, it must be multiplied by 2 again. If it uses DDR5, multiply by 4 instead. The higher the memory bandwidth, 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 amount of texture map elements (texels) that can be processed in one second. This number is calculated by multiplying the total number of texture units of the card by the core speed of the chip. The higher this number, the better the card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels applied per second.
Pixel Rate: Pixel rate is the maximum number of pixels the graphics card could possibly record to its local memory in one second - measured in millions of pixels per second. The figure is worked out by multiplying the number of colour ROPs by the the card's clock speed. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel rate also depends on lots of other factors, especially the memory bandwidth of the card - the lower the bandwidth is, the lower the ability to get to the maximum fill rate.