Compare any two graphics cards:
Radeon HD 6850 vs Radeon HD 6870
IntroThe Radeon HD 6850 uses a 40 nm design. AMD has clocked the core frequency at 775 MHz. The GDDR5 memory runs at a speed of 1000 MHz on this model. It features 960 SPUs along with 48 TAUs and 32 Rasterization Operator Units.
Compare all of that to the Radeon HD 6870, which uses a 40 nm design. AMD has clocked the core frequency at 900 MHz. The GDDR5 RAM works at a frequency of 1050 MHz on this card. It features 1120 SPUs as well as 56 Texture Address Units and 32 Rasterization Operator Units.
(No game benchmarks for this combination yet.)
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Theoretically speaking, the Radeon HD 6870 will be 5% faster than the Radeon HD 6850 in general, because of its greater data rate. (explain)
Texel RateThe Radeon HD 6870 will be much (more or less 35%) faster with regards to anisotropic filtering than the Radeon HD 6850. (explain)
Pixel RateThe Radeon HD 6870 should be just a bit (about 16%) faster with regards to anti-aliasing than the Radeon HD 6850, and also will 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 largest amount of data (counted in MB per second) that can be moved past the external memory interface in one second. The number is worked out by multiplying the bus width by the speed of its memory. If it uses DDR type RAM, the result should be multiplied by 2 again. If DDR5, multiply by 4 instead. The higher the card's memory bandwidth, the faster the card will be in general. It especially helps with AA, High Dynamic Range and high resolutions.
Texel Rate: Texel rate is the maximum texture map elements (texels) that can be applied per second. This is worked out by multiplying the total amount of texture units of the card by the core clock speed of the chip. The better this number, the better the video card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels in a second.
Pixel Rate: Pixel rate is the most pixels that the graphics card could possibly record to its local memory in a second - measured in millions of pixels per second. The figure is calculated by multiplying the amount of Render Output Units 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 is also dependant on quite a few other factors, especially the memory bandwidth - the lower the bandwidth is, the lower the potential to get to the maximum fill rate.