Compare any two graphics cards:
Radeon HD 5770 vs Radeon HD 6850
IntroThe Radeon HD 5770 has a GPU core speed of 850 MHz, and the 1024 MB of GDDR5 RAM runs at 1200 MHz through a 128-bit bus. It also is comprised of 800(160x5) SPUs, 40 TAUs, and 16 ROPs.
Compare those specs to the Radeon HD 6850, which comes with a core clock frequency of 775 MHz and a GDDR5 memory speed of 1000 MHz. It also makes use of a 256-bit memory bus, and makes use of a 40 nm design. It is made up of 960 SPUs, 48 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 6850 is 67% faster than the Radeon HD 5770 overall, because of its higher bandwidth. (explain)
Texel RateThe Radeon HD 6850 is just a bit (approximately 9%) more effective at texture filtering than the Radeon HD 5770. (explain)
Pixel RateIf running with high levels of AA is important to you, then the Radeon HD 6850 is a better choice, by far. (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 information (measured in megabytes per second) that can be moved over the external memory interface in one second. It's calculated by multiplying the interface width by its memory clock speed. If the card has DDR RAM, it must be multiplied by 2 once again. If it uses DDR5, multiply by 4 instead. The higher the bandwidth is, the better 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 can be applied per second. This is calculated by multiplying the total texture units by the core 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 in one second.
Pixel Rate: Pixel rate is the most pixels the video card could possibly write to the local memory per second - measured in millions of pixels per second. The number is worked out by multiplying the amount of colour ROPs 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 quite a few other factors, most notably the memory bandwidth of the card - the lower the bandwidth is, the lower the ability to get to the maximum fill rate.