Compare any two graphics cards:
GeForce GTX 660 vs Radeon HD 7770
IntroThe GeForce GTX 660 comes with core clock speeds of 980 MHz on the GPU, and 1502 MHz on the 2048 MB of GDDR5 memory. It features 960 SPUs as well as 80 Texture Address Units and 24 Rasterization Operator Units.
Compare those specifications to the Radeon HD 7770, which makes use of a 28 nm design. AMD has set the core speed at 1000 MHz. The GDDR5 memory is set to run at a speed of 1125 MHz on this particular model. It features 640 SPUs along with 40 TAUs and 16 ROPs.
(No game benchmarks for this combination yet.)
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Performance-wise, the GeForce GTX 660 should theoretically be quite a bit better than the Radeon HD 7770 in general. (explain)
Texel RateThe GeForce GTX 660 should be much (more or less 96%) better at texture filtering than the Radeon HD 7770. (explain)
Pixel RateIf using high levels of AA is important to you, then the GeForce GTX 660 is the winner, by a large margin. (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 information (measured in megabytes per second) that can be transferred across the external memory interface in a second. It is calculated by multiplying the card's interface width by the speed of its memory. If the card has DDR memory, the result should be multiplied by 2 once again. If DDR5, multiply by 4 instead. The better the card's memory bandwidth, the better the card will be in general. It especially helps with anti-aliasing, HDR and high resolutions.
Texel Rate: Texel rate is the maximum amount of texture map elements (texels) that are processed in one second. This number is calculated by multiplying the total amount of texture units by the core speed of the chip. The higher the texel rate, the better the video card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels processed in a second.
Pixel Rate: Pixel rate is the maximum amount of pixels the graphics card could possibly write to the local memory per second - measured in millions of pixels per second. The number is worked out by multiplying the amount of colour ROPs by the the card's 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 also depends on many other factors, most notably the memory bandwidth - the lower the memory bandwidth is, the lower the potential to get to the max fill rate.