Compare any two graphics cards:
Radeon HD 6870 vs Radeon HD 7850
IntroThe Radeon HD 6870 features a GPU core speed of 900 MHz, and the 1024 MB of GDDR5 RAM is set to run at 1050 MHz through a 256-bit bus. It also is made up of 1120 Stream Processors, 56 TAUs, and 32 ROPs.
Compare all that to the Radeon HD 7850, which comes with GPU core speed of 860 MHz, and 2048 MB of GDDR5 RAM set to run at 1200 MHz through a 256-bit bus. It also features 1024 Stream Processors, 64 Texture Address Units, and 32 Raster Operation Units.
(No game benchmarks for this combination yet.)
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
The Radeon HD 7850 should theoretically perform a bit faster than the Radeon HD 6870 in general. (explain)
Texel RateThe Radeon HD 7850 should be just a bit (more or less 9%) more effective at anisotropic filtering than the Radeon HD 6870. (explain)
Pixel RateThe Radeon HD 6870 should be just a bit (about 5%) faster with regards to FSAA than the Radeon HD 7850, and also should be capable of handling higher resolutions better. (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 largest amount of information (counted in MB per second) that can be transported over the external memory interface in a second. It's worked out by multiplying the card's bus width by its memory speed. If it uses DDR RAM, it should be multiplied by 2 once again. If DDR5, multiply by ANOTHER 2x. The higher the card's memory bandwidth, the better the card will be in general. It especially helps with anti-aliasing, HDR and high resolutions.
Texel Rate: Texel rate is the maximum amount of texture map elements (texels) that can be applied in one second. This is worked out by multiplying the total number of texture units by the core speed of the chip. The higher this number, the better the graphics card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels in a second.
Pixel Rate: Pixel rate is the maximum number of pixels that the graphics card can possibly record to its local memory in one second - measured in millions of pixels per second. The figure is worked out by multiplying the amount of colour ROPs by the clock speed of the card. ROPs (Raster Operations Pipelines - sometimes also referred to as Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel rate is also dependant on many other factors, most notably the memory bandwidth - the lower the memory bandwidth is, the lower the ability to reach the maximum fill rate.