Compare any two graphics cards:
GeForce GTX 580 vs Radeon HD 4850 512MB
IntroThe GeForce GTX 580 makes use of a 40 nm design. nVidia has set the core frequency at 772 MHz. The GDDR5 memory works at a frequency of 1002 MHz on this card. It features 512 SPUs as well as 64 TAUs and 48 Rasterization Operator Units.
Compare all of that to the Radeon HD 4850 512MB, which makes use of a 55 nm design. AMD has set the core speed at 625 MHz. The GDDR3 RAM runs at a speed of 993 MHz on this particular model. It features 800(160x5) SPUs along with 40 Texture Address Units and 16 Rasterization Operator Units.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
In theory, the GeForce GTX 580 should be 203% faster than the Radeon HD 4850 512MB in general, due to its greater data rate. (explain)
Texel RateThe GeForce GTX 580 should be quite a bit (more or less 98%) more effective at anisotropic filtering than the Radeon HD 4850 512MB. (explain)
Pixel RateIf running with high levels of AA is important to you, then the GeForce GTX 580 is a better choice, and very much so. (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 MB per second) that can be moved over the external memory interface in one second. It's worked out by multiplying the interface width by its memory speed. In the case of DDR type memory, it should be multiplied by 2 again. If DDR5, multiply by ANOTHER 2x. The higher the bandwidth is, the faster the card will be in general. It especially helps with AA, High Dynamic Range and high resolutions.
Texel Rate: Texel rate is the maximum amount of texture map elements (texels) that can be applied per second. This is calculated by multiplying the total number of texture units by the core speed of the chip. The higher the texel rate, 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 maximum number of pixels that the graphics card can possibly write to the local memory in a second - measured in millions of pixels per second. The number is worked out by multiplying the number of Render Output Units by the the core clock speed. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel rate is also dependant on lots of other factors, most notably the memory bandwidth - the lower the bandwidth is, the lower the ability to reach the max fill rate.