This is a technical problem I have been experiencing for some time, but have only just solved. Web searches revealed that a lot of people have this problem, but I was not able to find a solid solution. So, I’m posting my solution here to my blog so that maybe somebody else can find it.
The Setup
I have two external monitors attached to my Windows laptop through a docking station. For a long time, both monitors were identical (Dell S2415H) 24″ 1920×1080 flat screen monitors. Then I saw a larger (Acer EB321HQU) 31.5″ 2048×1152 flat screen monitor on sale for a really good price. The Acer is almost comically large for my desk, especially with it looming over my normal-sized laptop.
Now, both monitors have always been connected to the docking station using HDMI cables, but the docking station only has one HDMI jack and two DisplayPort jacks. I have the Acer monitor connected to the one HDMI jack, and connect the Dell monitor through an HDMI to DP adapter.
The Problem
Video on the Dell monitor “jitters”. Moving windows around creates “ghost” images on the display. The second monitor was basically unusable in this state. Now I thought that the problem was caused by the HDMI-DP adapter, but switching the connections around did not make any difference. The Dell always jittered, even if it was connected directly with the Acer on the adapter.
I did not have this problem when I was using the two identical Dell monitors. I could not figure out what was causing the problem, so I stopped using the Dell monitor with my personal laptop, and connected it full time to my work laptop.
The Solution
Open the Display Settings dialog, and select the jittery monitor. Open the “Advanced display settings” for the jittery monitor, and choose a different frequency from the “Refresh rate” menu. That’s it!
The jitter problem seems to have been caused by a refresh rate mismatch between the two monitors. The Acer recommends a refresh rate of 59.940 Hz, so having the Dell configured for a different rate was a problem.
Syncing the two rates solved the problem. No more jitters!