Compare any two graphics cards:
GeForce GTX 660 vs Radeon HD 7770
IntroThe GeForce GTX 660 features a GPU core clock speed of 980 MHz, and the 2048 MB of GDDR5 memory is set to run at 1502 MHz through a 192-bit bus. It also features 960 Stream Processors, 80 Texture Address Units, and 24 Raster Operation Units.
Compare all of that to the Radeon HD 7770, which has a GPU core clock speed of 1000 MHz, and 1024 MB of GDDR5 RAM running at 1125 MHz through a 128-bit bus. It also is made up of 640 Stream Processors, 40 Texture Address Units, and 16 Raster Operation Units.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Theoretically, the GeForce GTX 660 should perform quite a bit faster than the Radeon HD 7770 in general. (explain)
Texel RateThe GeForce GTX 660 should be quite a bit (approximately 96%) faster with regards to anisotropic filtering than the Radeon HD 7770. (explain)
Pixel RateThe GeForce GTX 660 should be quite a bit (about 47%) faster with regards to FSAA than the Radeon HD 7770, and also should be 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: Bandwidth is the largest amount of information (measured in megabytes per second) that can be transported over the external memory interface within a second. It's worked out by multiplying the interface width by its memory clock speed. If the card has DDR type RAM, it should be multiplied by 2 again. If it uses DDR5, multiply by 4 instead. The better the bandwidth is, 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 amount of texture map elements (texels) that are processed in one second. This figure is worked out by multiplying the total amount 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 per second.
Pixel Rate: Pixel rate is the maximum number of pixels that the graphics chip could possibly write to its local memory in a second - measured in millions of pixels per second. The number is calculated by multiplying the amount of Render Output Units by the clock speed of the card. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel rate also depends on lots of other factors, most notably the memory bandwidth - the lower the memory bandwidth is, the lower the potential to get to the maximum fill rate.