Hello, I have a 2011 iMac, running High Sierra, and have gotten a weird static like graphics corruption that happens somewhat intermittently. I was able to do a screen recording and uploaded it to youtube so you know exactly what I am talking about: Do you think this is something related to high sierra, or is it an indication of an impending failure of my iMac? Has anyone else seen anything like this. FYI, I have seen this while both using iTunes & Safari. Thanks for any insight.