I got my AMD card in (a 6970 used to be precise) for AMD overdrive testing. I used http://www.lagom.nl/lcd-test/response_time.php
for most of the response time testing. First of all overdrive is mostly not used anymore as with a monitor running under 8-10ms response time the side effects are said to not be worth it due to reduced possible monitor live time and color precision issues. I myself thought it was worth 20 bucks to test on this monitor given its already very good response.
First off the testing method i used was the lagom response time pattern being shot by a high speed camera and refresh rate multitool shot by a high speed camera. The percentages i give are a pixel count from left to right difference in the ghosting effect from each test tool recorded by the camera close enough to see the whole pattern and see the individual pixel with a sharpness increase(which may slightly through off the results but this should be a fraction of a percent or up to 2 pixels, as this is completely indistinguishable to the eye your going to have to bare with me on it)
Stock 100 overdrive gave a 11% difference on average between each color stream in terms of ghosting or response. This is equivalent to the 6.4ms response that was tested in another review(forget the user right now) so the resulting response would be 5.7ms
The 150 overdrive gave a 14% difference in all color bands on average(excluding 80 point grey or blue see below) this is relative to a 5.5ms response from 6.4 stock.
The 200 overdrrive setting just through the monitor into test mode(which took safe mode to fix)
Over my testing i also found that the pixel response is effected just as much by the color retention since light blue or grey gave a anomalous reading ranging up to a 8-11ms response and overdrive made it worse at overclock speeds. After setting the monitor to 60hz the response variance between light grey/blue was almost none existent from the rest of the color spectrum. Not sure what is going on here but it seems the qnix doesn't like light grey/blue(or at least mine).
Overall i could not see any color shift or pixel drag from the resulting pixel overvoltage which does show a good power regulation throughout the panel. Ultimately i still don't think it is worth the risk to go from 6.4ms to 5.7ms.
Hope someone found this interesting and i will be selling a 6970 LOL