Compare any two graphics cards:
Radeon HD 6850 vs Radeon HD 6870
IntroThe Radeon HD 6850 comes with a core clock speed of 775 MHz and a GDDR5 memory frequency of 1000 MHz. It also uses a 256-bit bus, and uses a 40 nm design. It is comprised of 960 SPUs, 48 Texture Address Units, and 32 ROPs.
Compare those specifications to the Radeon HD 6870, which features a core clock speed of 900 MHz and a GDDR5 memory speed of 1050 MHz. It also features a 256-bit bus, and uses a 40 nm design. It is made up of 1120 SPUs, 56 TAUs, and 32 ROPs.
(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 higher bandwidth. (explain)
Texel RateThe Radeon HD 6870 will be a lot (about 35%) more effective at anisotropic filtering than the Radeon HD 6850. (explain)
Pixel RateThe Radeon HD 6870 will be a small bit (more or less 16%) faster with regards to full screen anti-aliasing than the Radeon HD 6850, 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.
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 (in units of megabytes per second) that can be transported past the external memory interface in a second. It's worked out by multiplying the card's interface width by the speed of its memory. If the card has DDR RAM, it must 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 high resolutions.
Texel Rate: Texel rate is the maximum number of texture map elements (texels) that can be applied per second. This figure is worked out by multiplying the total texture units of the card by the core clock speed of the chip. The higher this number, the better the 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 maximum amount of pixels the video card can possibly write to the local memory per second - measured in millions of pixels per second. The figure is calculated by multiplying the number 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 many other factors, especially the memory bandwidth - the lower the bandwidth is, the lower the ability to get to the maximum fill rate.