Compare any two graphics cards:
Radeon HD 6850 vs Radeon HD 6870
IntroThe Radeon HD 6850 has a clock frequency of 775 MHz and a GDDR5 memory speed of 1000 MHz. It also uses a 256-bit memory bus, and uses a 40 nm design. It is made up of 960 SPUs, 48 TAUs, and 32 Raster Operation Units.
Compare those specs to the Radeon HD 6870, which comes with GPU core speed of 900 MHz, and 1024 MB of GDDR5 memory running at 1050 MHz through a 256-bit bus. It also features 1120 Stream Processors, 56 TAUs, and 32 Raster Operation Units.
(No game benchmarks for this combination yet.)
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
In theory, the Radeon HD 6870 will be 5% quicker than the Radeon HD 6850 in general, because of its greater data rate. (explain)
Texel RateThe Radeon HD 6870 should be a lot (approximately 35%) better at anisotropic filtering than the Radeon HD 6850. (explain)
Pixel RateThe Radeon HD 6870 is just a bit (approximately 16%) faster with regards to full screen anti-aliasing than the Radeon HD 6850, and also should be able to handle higher screen resolutions while still performing well. (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 information (in units of megabytes per second) that can be moved over the external memory interface in one second. The number is calculated by multiplying the bus width by the speed of its memory. If the card has DDR RAM, it should be multiplied by 2 once again. If it uses DDR5, multiply by 4 instead. The higher the card's memory bandwidth, the faster the card will be in general. It especially helps with anti-aliasing, HDR and higher screen resolutions.
Texel Rate: Texel rate is the maximum amount of texture map elements (texels) that are applied per second. This is calculated by multiplying the total number of texture units by the core clock speed of the chip. The better this number, the better the card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels processed in one second.
Pixel Rate: Pixel rate is the maximum amount of pixels that the graphics chip can possibly write to its local memory in a second - measured in millions of pixels per second. The number is worked out by multiplying the amount of Raster Operations Pipelines by the clock speed of the card. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel output rate also depends on quite a few other factors, especially the memory bandwidth of the card - the lower the memory bandwidth is, the lower the ability to reach the maximum fill rate.