Compare any two graphics cards:
GeForce GTX 580 vs Radeon HD 7850
IntroThe GeForce GTX 580 features a GPU clock speed of 772 MHz, and the 1536 MB of GDDR5 memory runs at 1002 MHz through a 384-bit bus. It also is comprised of 512 SPUs, 64 TAUs, and 48 Raster Operation Units.
Compare those specifications to the Radeon HD 7850, which uses a 28 nm design. AMD has clocked the core speed at 860 MHz. The GDDR5 memory is set to run at a speed of 1200 MHz on this particular card. It features 1024 SPUs along with 64 TAUs and 32 ROPs.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Theoretically speaking, the GeForce GTX 580 will be 25% faster than the Radeon HD 7850 overall, because of its higher data rate. (explain)
Texel RateThe Radeon HD 7850 will be a small bit (about 11%) more effective at anisotropic filtering than the GeForce GTX 580. (explain)
Pixel RateThe GeForce GTX 580 is much (more or less 35%) better at FSAA than the Radeon HD 7850, and also will be capable of handling higher resolutions without losing too much performance. (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: Bandwidth is the maximum amount of data (counted in MB per second) that can be transferred across the external memory interface in one second. It's worked out by multiplying the interface width by its memory speed. If the card has DDR type memory, the result should be multiplied by 2 once again. If DDR5, multiply by 4 instead. The higher the memory bandwidth, the faster the card will be in general. It especially helps with AA, HDR and high resolutions.
Texel Rate: Texel rate is the maximum texture map elements (texels) that can be processed per second. This is calculated by multiplying the total number of texture units by the core speed of the chip. The better the texel rate, the better the card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels processed per second.
Pixel Rate: Pixel rate is the maximum amount of pixels the video card could possibly record to the local memory in a second - measured in millions of pixels per second. Pixel rate is worked out by multiplying the number of Raster Operations Pipelines by the clock 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 fill rate is also dependant on quite a few other factors, most notably the memory bandwidth - the lower the memory bandwidth is, the lower the potential to get to the max fill rate.