Compare any two graphics cards:
GeForce GTX 660 vs Radeon HD 7870
IntroThe GeForce GTX 660 makes use of a 28 nm design. nVidia has clocked the core frequency at 980 MHz. The GDDR5 RAM is set to run at a frequency of 1502 MHz on this model. It features 960 SPUs along with 80 Texture Address Units and 24 ROPs.
Compare those specifications to the Radeon HD 7870, which features GPU core speed of 1000 MHz, and 2048 MB of GDDR5 RAM running at 1200 MHz through a 256-bit bus. It also is comprised of 1280 SPUs, 80 Texture Address Units, and 32 Raster Operation Units.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
In theory, the Radeon HD 7870 is 7% quicker than the GeForce GTX 660 overall, due to its greater bandwidth. (explain)
Texel RateThe Radeon HD 7870 is a bit (approximately 2%) more effective at texture filtering than the GeForce GTX 660. (explain)
Pixel RateIf using a high screen resolution is important to you, then the Radeon HD 7870 is a better choice, and very much so. (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 (counted in megabytes per second) that can be transported across the external memory interface in one second. The number is worked out by multiplying the interface width by its memory speed. If it uses DDR RAM, it must be multiplied by 2 again. If DDR5, multiply by 4 instead. The higher the bandwidth is, the better the card will be in general. It especially helps with anti-aliasing, HDR and higher screen resolutions.
Texel Rate: Texel rate is the maximum number of texture map elements (texels) that can be processed in one second. This is calculated by multiplying the total texture units of the card by the core speed of the chip. The higher the texel rate, the better the video card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels processed per second.
Pixel Rate: Pixel rate is the maximum number of pixels that the graphics chip could possibly write to its local memory in one second - measured in millions of pixels per second. The number is worked out by multiplying the number of Render Output Units by the the card's clock speed. ROPs (Raster Operations Pipelines - sometimes also referred to as Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel fill rate is also dependant on lots of other factors, especially the memory bandwidth of the card - the lower the bandwidth is, the lower the ability to get to the max fill rate.