Compare any two graphics cards:
GeForce GTX 660 vs Radeon HD 7770
IntroThe GeForce GTX 660 uses a 28 nm design. nVidia has set the core frequency at 980 MHz. The GDDR5 RAM is set to run at a frequency of 1502 MHz on this specific model. It features 960 SPUs along with 80 TAUs and 24 Rasterization Operator Units.
Compare those specs to the Radeon HD 7770, which features a core clock speed of 1000 MHz and a GDDR5 memory frequency of 1125 MHz. It also features a 128-bit memory bus, and uses a 28 nm design. It is comprised of 640 SPUs, 40 Texture Address Units, and 16 ROPs.
(No game benchmarks for this combination yet.)
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
In theory, the GeForce GTX 660 should perform much faster than the Radeon HD 7770 in general. (explain)
Texel RateThe GeForce GTX 660 is much (more or less 96%) better at anisotropic filtering than the Radeon HD 7770. (explain)
Pixel RateThe GeForce GTX 660 is much (approximately 47%) faster with regards to AA than the Radeon HD 7770, and also able to handle higher screen 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 maximum amount of data (measured in MB per second) that can be moved across the external memory interface in one second. The number is calculated by multiplying the card's interface width by its memory speed. If it uses DDR type RAM, it must be multiplied by 2 again. If it uses DDR5, multiply by 4 instead. The better the memory bandwidth, the faster the card will be in general. It especially helps with anti-aliasing, High Dynamic Range and higher screen resolutions.
Texel Rate: Texel rate is the maximum amount of texture map elements (texels) that are applied in one second. This number is calculated by multiplying the total number of texture units by the core speed of the chip. The higher 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 amount of pixels that the graphics card could possibly record to its local memory in one second - measured in millions of pixels per second. The figure is worked out by multiplying the amount of Raster Operations Pipelines by the the core clock speed. ROPs (Raster Operations Pipelines - also sometimes called 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, most notably the memory bandwidth - the lower the memory bandwidth is, the lower the potential to get to the maximum fill rate.