Ditherig application (so disabling dithering functions on Intel HD), and swtiching from 8 bit to 6 and disabling dithering from registry lvl in Radeon Card also helps me, so I guess disconnecting Power Supply for sure is disabling something related with dithering. It's possible that some other options that are uncomfortable for our eyes are disabled aswell, but I guess dithering is the main one. It could be very good starting point for example for Intel engineers to investigate what is straining us and what option could be added in next driver releases, but I bet it would be very hard to contact them in so direct way and encourage them to do so.
Quad43 Yep, even manual plugging and unplugging powr is fine, but the biggest disadvantage of this solution is intense battery usage which is causing her short lifetime.