6850 Overclock question

vicari0us

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Dec 25, 2011
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I recently got 2 Gigabyte HD6850's which come OC'd at 820. Just using the basic AMD Vision control center utility to overclock, I wanted to check each one individually for overclocking stability before setting up crossfire. In the Performance tab>Graphics Overdrive with Overdrive enabled, the speeds show up as normal 820GPU/1050mem and the slider bars adjust from 600-985 for GPU and 1050-1260 for memory. Overclocking works fine, seemed happy at 900/1150. ok now here is what I am confused by...

Removed 1st card and installed 2nd card to do same tests. At the same performance>overdrive page the same base clock speeds are there (820/1050) but the sliders have changed to only 600-850 for GPU and 1050-1150 for memory... WTF? Why would the 2nd identical card have a lesser overclock range... they both test nearly identical in Cinebench at stock speeds so, what am I missing here?