Update The issue is that despite all the WOW TBC Gold work I did and setting my FPS at the level that kept my card at a lower than 50% load, I was still seeing flickering while running a Kara raid the other night. So I disabled Freesync completely and it seemed to resolve the problem.

It was disabled through both the monitors (both are identical brands but have different sizes and models) and also my AMD GPU settings. This seems to have fixed the issue. I'll be watching to see any additional issues that come up.

Original Post: I've noticed flickering issues, however, I'd call it full-on studdering. It's been happening for a while in a way that makes it hard to identify. It was at the point that it was making me insane, so I decided to research.

It is now that Windows allows multiple monitors to refresh rates. This means that Microsoft has finally addressed a long-standing issue with Windows handling of multi-monitor refresh rates. Till now, Windows 10's Desktop Window Manager (DWM) was causing frame-skips as well as stutters, when using multiple monitors that had different refresh rates. This issue is solved by Windows 10's DWM 20H1, which is able to support hardware-accelerated GPU scheduling (WDDM 2.7). A Reddit user has demonstrated this issue.

After I realized this issue I switched from my main monitor running 144hz and a 60hz secondary monitor to all my monitors running 144hz. I made this change because I did not want changing my system now and also because the 60hz display was long overdue to upgrade.

However , in doing so, I upgraded to a larger main monitor which meant that my GPU was now running a lot more pixels and both at that high a rate of refresh. My GPU was now required to perform, despite being fine for classic WoW. It was not able to handle the task.

I noticed that , even with all addons off, regardless of matter what version of DX I picked, VSync would be on or off regardless of it was that my GPU was reaching its limits, the game would show some amount of flickering. With all the lush foliage and zones like Nagrand My GPU would be forced to the limit which eventually led to throttling.

It seems WoW doesn't like my GPU throttle. Although my CPU wasn't sweating, I saw the flickering when my GPU was at its limit. The flickering got worse due to add-ons.

In this way, I reduced my game FPS limit to 60 , and everything became much more smooth. Although it's a bit cheap Burning Crusade Classic Gold annoying that you'll be able to see your rear at 60 after playing for some time but it's a lot better than the flickering I experienced.