Tue, 20 Mar 2018 20:18:16 +0000 Xianwen Chen <xianwen.c...@nina.no> > [...] > If you are right that humans are not able to see the difference between 60 Hz > and 59.95 Hz, then something is wrong with xrandr that the actual refresh > rate is quite below 60, not as much as 59.95 as reported by xrandr, because I > can clearly see the flickering. I do not think that this is a minimal thing, > because the flickering screen makes my head dizzy. > > I do not think that there is problem with the connection cable, as there was > no such problem when the same external monitor is connected to a ThinkPad R52 > using the same VGA cable a couple of days ago. I can check the cable > connection again tomorrow. > > I am sceptical whether there is any other source of distortion. I don't know > where to start if there should be distortion. > > Yours sincerely, > Xianwen >
Hi Xianwen, Most probably it is NOT the refresh rate and xrandr is reporting it fine. I would recommend you find the source of interference: in a closed ground loop, electrical current between various signalling cables, nearby USB ?! cables close to the video cable or other signal cables, and power circuit plug orientation, noise in the electric mains power from other equipment. Also some monitors have PWM flickering quite visible on low settings, yet I suspect you have a signalling interference and closed ground loop case. Kind regards, Anton Lazarov
