Compare any two graphics cards:
GeForce GTX 660 vs Radeon HD 7870
IntroThe GeForce GTX 660 has core speeds of 980 MHz on the GPU, and 1502 MHz on the 2048 MB of GDDR5 RAM. It features 960 SPUs as well as 80 TAUs and 24 Rasterization Operator Units.
Compare those specifications to the Radeon HD 7870, which uses a 28 nm design. AMD has set the core speed at 1000 MHz. The GDDR5 memory works at a speed of 1200 MHz on this particular card. It features 1280 SPUs along with 80 TAUs and 32 Rasterization Operator Units.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Theoretically speaking, the Radeon HD 7870 should perform a little bit faster than the GeForce GTX 660 in general. (explain)
Texel RateThe Radeon HD 7870 should be a small bit (about 2%) better at AF than the GeForce GTX 660. (explain)
Pixel RateIf using lots of anti-aliasing is important to you, then the Radeon HD 7870 is superior to the GeForce GTX 660, 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 transferred over the external memory interface within a second. It is worked out by multiplying the bus width by its memory clock speed. In the case of DDR type memory, it must be multiplied by 2 again. If it uses DDR5, multiply by ANOTHER 2x. The higher the memory bandwidth, the better the card will be in general. It especially helps with AA, High Dynamic Range and high resolutions.
Texel Rate: Texel rate is the maximum number of texture map elements (texels) that can be processed in one second. This number is worked out by multiplying the total amount of texture units of the card by the core clock speed of the chip. The better this number, the better the video card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels processed in one second.
Pixel Rate: Pixel rate is the maximum number of pixels the graphics card can possibly write to its local memory per second - measured in millions of pixels per second. The figure is calculated by multiplying the number of Raster Operations Pipelines by the the core speed of the card. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel output rate is also dependant on many other factors, most notably the memory bandwidth of the card - the lower the memory bandwidth is, the lower the potential to get to the max fill rate.