Compare any two graphics cards:
GeForce GTX 660 vs Radeon HD 7870
IntroThe GeForce GTX 660 comes with a GPU clock speed of 980 MHz, and the 2048 MB of GDDR5 RAM is set to run at 1502 MHz through a 192-bit bus. It also is made up of 960 SPUs, 80 TAUs, and 24 Raster Operation Units.
Compare all of that to the Radeon HD 7870, which uses a 28 nm design. AMD has clocked the core speed at 1000 MHz. The GDDR5 RAM works at a speed of 1200 MHz on this particular card. It features 1280 SPUs as well as 80 Texture Address Units and 32 Rasterization Operator Units.
(No game benchmarks for this combination yet.)
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
The Radeon HD 7870 should in theory perform a bit faster than the GeForce GTX 660 in general. (explain)
Texel RateThe Radeon HD 7870 is a bit (more or less 2%) more effective at texture filtering than the GeForce GTX 660. (explain)
Pixel RateIf using lots of anti-aliasing is important to you, then the Radeon HD 7870 is the winner, 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: Memory bandwidth is the maximum amount of data (measured in MB per second) that can be transported across the external memory interface in one second. The number is worked out by multiplying the card's bus width by its memory clock speed. If the card has DDR type memory, it should be multiplied by 2 again. If DDR5, multiply by 4 instead. The higher the card's memory bandwidth, the faster the card will be in general. It especially helps with anti-aliasing, HDR and higher screen resolutions.
Texel Rate: Texel rate is the maximum texture map elements (texels) that can be applied per second. This figure is calculated by multiplying the total number of texture units of the card by the core clock speed of the chip. The higher the texel rate, the better the card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels applied per second.
Pixel Rate: Pixel rate is the most pixels the video card could possibly record to its local memory in one second - measured in millions of pixels per second. The number is worked out by multiplying the number of ROPs by the the core 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 is also dependant on quite a few other factors, especially the memory bandwidth of the card - the lower the bandwidth is, the lower the potential to reach the max fill rate.