Compare any two graphics cards:
GeForce GTX 660 vs Radeon HD 7850
IntroThe GeForce GTX 660 uses a 28 nm design. nVidia has set the core speed at 980 MHz. The GDDR5 memory is set to run at a speed of 1502 MHz on this particular card. It features 960 SPUs as well as 80 TAUs and 24 ROPs.
Compare all that to the Radeon HD 7850, which features a GPU core clock speed of 860 MHz, and 2048 MB of GDDR5 RAM running at 1200 MHz through a 256-bit bus. It also is made up of 1024 SPUs, 64 TAUs, and 32 ROPs.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
In theory, the Radeon HD 7850 should perform a bit faster than the GeForce GTX 660 overall. (explain)
Texel RateThe GeForce GTX 660 will be much (more or less 42%) faster with regards to texture filtering than the Radeon HD 7850. (explain)
Pixel RateThe Radeon HD 7850 will be just a bit (approximately 17%) faster with regards to full screen anti-aliasing than the GeForce GTX 660, and also capable of handling higher resolutions more effectively. (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 largest amount of data (in units of megabytes per second) that can be transported across the external memory interface in a second. It is worked out by multiplying the interface width by its memory clock speed. In the case of DDR type memory, it should be multiplied by 2 again. If DDR5, multiply by 4 instead. The better the card's memory bandwidth, the faster the card will be in general. It especially helps with AA, High Dynamic Range and higher screen resolutions.
Texel Rate: Texel rate is the maximum number of texture map elements (texels) that are applied per second. This figure is worked out by multiplying the total texture units of the card by the core clock speed of the chip. The better this number, the better the video card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels applied in one second.
Pixel Rate: Pixel rate is the most pixels that the graphics card could possibly record to the local memory in one second - measured in millions of pixels per second. The figure is calculated by multiplying the amount of Render Output Units by the the core clock speed. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel fill rate is also dependant on many other factors, especially the memory bandwidth - the lower the memory bandwidth is, the lower the potential to get to the maximum fill rate.