However, I did it through upgrading to WOW TBC Gold a larger main screen. This meant that my GPU was now delivering more pixels , at a greater refresh rate. My GPU, which had been fine prior to something as simple as Classic WoW, was actually having to put in the work. It was not up to the job.
I observed that even with all addons turned off, no matter what version of DX I picked, VSync is either on or off however I was doing to push my GPU to its limits, the game would exhibit some flashing in the background at times. With all its lush foliage and zones like Nagrand, my GPU would be overloaded to 100% which eventually led to being throttled.
It seems that WoW does not appreciate my GPU throttle. Even though my CPU was not sweating, it was evident that there was flickering of my GPU when it was at its limits. The flickering became more noticeable due to extensions.
My in-game FPS limit was set at 60. This made my gaming more enjoyable. Although it's annoying when you can see your back at 60 after buy WOW TBC Classic Gold a few minutes of playing, it is still significantly better than my flickering experience.