Compare any two graphics cards:
Radeon HD 5770 vs Radeon HD 6850
IntroThe Radeon HD 5770 makes use of a 40 nm design. AMD has clocked the core frequency at 850 MHz. The GDDR5 RAM runs at a frequency of 1200 MHz on this particular model. It features 800(160x5) SPUs as well as 40 TAUs and 16 ROPs.
Compare those specs to the Radeon HD 6850, which has a core clock speed of 775 MHz and a GDDR5 memory speed of 1000 MHz. It also uses a 256-bit bus, and makes use of a 40 nm design. It is made up of 960 SPUs, 48 TAUs, and 32 ROPs.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Theoretically speaking, the Radeon HD 6850 is 67% faster than the Radeon HD 5770 in general, because of its higher data rate. (explain)
Texel RateThe Radeon HD 6850 is a small bit (about 9%) better at AF than the Radeon HD 5770. (explain)
Pixel RateThe Radeon HD 6850 should be a lot (about 82%) faster with regards to AA than the Radeon HD 5770, and also able to handle higher screen resolutions without losing too much performance. (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.
Radeon HD 5770
Radeon HD 6850
Memory Bandwidth: Memory bandwidth is the largest amount of data (counted in MB per second) that can be transferred over the external memory interface within a second. It's calculated by multiplying the interface width by the speed of its memory. If the card has DDR type memory, it must be multiplied by 2 once again. If DDR5, multiply by 4 instead. The better the card's 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 per second. This figure is calculated by multiplying the total amount of texture units of the card by the core clock speed of the chip. The higher this number, the better the video 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 maximum amount of pixels that the graphics card could possibly write to the local memory in one second - measured in millions of pixels per second. Pixel rate is worked out by multiplying the amount of Render Output Units by the the core clock speed. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel fill rate also depends on lots of other factors, especially the memory bandwidth of the card - the lower the memory bandwidth is, the lower the potential to reach the max fill rate.
Radeon HD 5770
Radeon HD 6850