Compare any two graphics cards:
Radeon HD 6850 vs Radeon HD 7770
IntroThe Radeon HD 6850 has a GPU clock speed of 775 MHz, and the 1024 MB of GDDR5 RAM runs at 1000 MHz through a 256-bit bus. It also is comprised of 960 Stream Processors, 48 Texture Address Units, and 32 ROPs.
Compare those specifications to the Radeon HD 7770, which makes use of a 28 nm design. AMD has clocked the core frequency at 1000 MHz. The GDDR5 memory works at a speed of 1125 MHz on this card. It features 640 SPUs as well as 40 Texture Address Units and 16 Rasterization Operator Units.
(No game benchmarks for this combination yet.)
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Theoretically speaking, the Radeon HD 6850 is 78% quicker than the Radeon HD 7770 overall, due to its higher data rate. (explain)
Texel RateThe Radeon HD 7770 will be a bit (approximately 8%) better at AF than the Radeon HD 6850. (explain)
Pixel RateIf using a high resolution is important to you, then the Radeon HD 6850 is superior to the Radeon HD 7770, 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 maximum amount of data (measured in MB per second) that can be transferred past the external memory interface in one second. It's calculated by multiplying the card's interface width by the speed of its memory. If it uses DDR memory, it should be multiplied by 2 once again. If DDR5, multiply by 4 instead. The better the bandwidth is, the better the card will be in general. It especially helps with AA, HDR and higher screen resolutions.
Texel Rate: Texel rate is the maximum amount of texture map elements (texels) that are processed in one second. This number is calculated 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 video card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels applied in a second.
Pixel Rate: Pixel rate is the most pixels that the graphics chip can possibly record to the local memory in one second - measured in millions of pixels per second. The figure is calculated by multiplying the number of Raster Operations Pipelines by the the card's clock speed. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel rate also depends 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.