Compare any two graphics cards:
GeForce GTX 660 vs Radeon HD 7850
IntroThe GeForce GTX 660 comes with a core clock frequency of 980 MHz and a GDDR5 memory speed of 1502 MHz. It also features a 192-bit bus, and uses a 28 nm design. It is comprised of 960 SPUs, 80 Texture Address Units, and 24 ROPs.
Compare those specs to the Radeon HD 7850, which comes with a core clock speed of 860 MHz and a GDDR5 memory frequency of 1200 MHz. It also uses a 256-bit bus, and uses a 28 nm design. It features 1024 SPUs, 64 Texture Address Units, and 32 Raster Operation Units.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
In theory, the Radeon HD 7850 should be 7% quicker than the GeForce GTX 660 in general, because of its higher bandwidth. (explain)
Texel RateThe GeForce GTX 660 is quite a bit (more or less 42%) more effective at anisotropic filtering than the Radeon HD 7850. (explain)
Pixel RateThe Radeon HD 7850 should be just a bit (more or less 17%) faster with regards to anti-aliasing than the GeForce GTX 660, and also able to handle higher 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 information (counted in megabytes per second) that can be moved across the external memory interface in a second. The number is calculated by multiplying the card's bus width by the speed of its memory. If the card has DDR RAM, it should 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, High Dynamic Range and high resolutions.
Texel Rate: Texel rate is the maximum number of texture map elements (texels) that are processed in one second. This number is calculated by multiplying the total number of texture units of the card by the core clock speed of the chip. The better this number, the better the graphics 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 number of pixels that the graphics chip can possibly record to the local memory in one second - measured in millions of pixels per second. The number is calculated by multiplying the number of ROPs by the the card's clock speed. 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 output rate also depends on quite a few other factors, especially the memory bandwidth of the card - the lower the memory bandwidth is, the lower the potential to reach the max fill rate.