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 memory runs at 1200 MHz through a 128-bit bus. It also is made up of 800(160x5) SPUs, 40 Texture Address Units, and 16 ROPs.
Compare all of that to the Radeon HD 6850, which uses a 40 nm design. AMD has clocked the core speed at 775 MHz. The GDDR5 memory works at a speed of 1000 MHz on this model. It features 960 SPUs as well as 48 Texture Address Units and 32 Rasterization Operator Units.
(No game benchmarks for this combination yet.)
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
In theory, the Radeon HD 6850 will be 67% faster than the Radeon HD 5770 in general, because of its higher bandwidth. (explain)
Texel RateThe Radeon HD 6850 should be a bit (more or less 9%) better 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 superior to the Radeon HD 5770, 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: Memory bandwidth is the max amount of data (in units of MB per second) that can be transported across the external memory interface in one second. It's worked out by multiplying the bus width by its memory clock speed. If the card has DDR type memory, the result should be multiplied by 2 once again. If it uses DDR5, multiply by 4 instead. The better the memory bandwidth, 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 texture map elements (texels) that are processed per second. This number is calculated by multiplying the total texture units by the core speed of the chip. The higher the texel rate, the better the video card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels per second.
Pixel Rate: Pixel rate is the maximum amount of pixels that the graphics card 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 amount of colour ROPs by the the core speed of the card. 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 output rate is also dependant on lots of other factors, especially the memory bandwidth of the card - the lower the bandwidth is, the lower the potential to get to the maximum fill rate.