Compare any two graphics cards:
GeForce GTX 660 vs Radeon HD 7770
IntroThe GeForce GTX 660 makes use of a 28 nm design. nVidia has set the core frequency at 980 MHz. The GDDR5 RAM is set to run at a speed of 1502 MHz on this particular card. It features 960 SPUs along with 80 Texture Address Units and 24 ROPs.
Compare those specifications to the Radeon HD 7770, which features a core clock frequency of 1000 MHz and a GDDR5 memory speed of 1125 MHz. It also makes use of a 128-bit bus, and uses a 28 nm design. It features 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)
Theoretically speaking, the GeForce GTX 660 will be 100% quicker than the Radeon HD 7770 overall, because of its higher bandwidth. (explain)
Texel RateThe GeForce GTX 660 should be quite a bit (more or less 96%) better at texture filtering than the Radeon HD 7770. (explain)
Pixel RateThe GeForce GTX 660 is quite a bit (about 47%) faster with regards to anti-aliasing than the Radeon HD 7770, and able to handle higher resolutions better. (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 max amount of data (in units of megabytes per second) that can be moved past 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 it uses DDR type RAM, it must be multiplied by 2 once 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, HDR and higher screen resolutions.
Texel Rate: Texel rate is the maximum number of texture map elements (texels) that can be processed per second. This figure is worked out by multiplying the total texture units by the core speed of the chip. The better the texel rate, 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 maximum amount of pixels that the graphics card can possibly write to its local memory in one second - measured in millions of pixels per second. Pixel rate is worked out by multiplying the number of Raster Operations Pipelines by the the core clock speed. ROPs (Raster Operations Pipelines - aka 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 ability to get to the max fill rate.