Compare any two graphics cards:
GeForce GTX 660 vs Radeon HD 7850
IntroThe GeForce GTX 660 features a GPU core clock speed of 980 MHz, and the 2048 MB of GDDR5 RAM runs at 1502 MHz through a 192-bit bus. It also is comprised of 960 Stream Processors, 80 Texture Address Units, and 24 Raster Operation Units.
Compare all that to the Radeon HD 7850, which makes use of a 28 nm design. AMD has clocked the core speed at 860 MHz. The GDDR5 memory runs at a frequency of 1200 MHz on this model. It features 1024 SPUs along with 64 Texture Address Units and 32 ROPs.
(No game benchmarks for this combination yet.)
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
In theory, the Radeon HD 7850 should be just a bit faster than the GeForce GTX 660 in general. (explain)
Texel RateThe GeForce GTX 660 will be quite a bit (approximately 42%) better at AF than the Radeon HD 7850. (explain)
Pixel RateIf running with high levels of AA is important to you, then the Radeon HD 7850 is superior to the GeForce GTX 660, but only just. (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 max amount of information (counted in MB per second) that can be transferred past the external memory interface within a second. It's calculated by multiplying the interface width by its memory speed. If it uses DDR RAM, it should be multiplied by 2 once again. If it uses DDR5, multiply by ANOTHER 2x. The better the card's memory bandwidth, the faster the card will be in general. It especially helps with AA, High Dynamic Range and higher screen resolutions.
Texel Rate: Texel rate is the maximum number of texture map elements (texels) that are processed per second. This number is worked out by multiplying the total texture units of the card by the core clock speed of the chip. The better the texel rate, the better the graphics card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels per second.
Pixel Rate: Pixel rate is the maximum number of pixels the video card can 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 - also sometimes called Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel output rate is also dependant on lots of other factors, most notably the memory bandwidth - the lower the memory bandwidth is, the lower the potential to reach the max fill rate.