I recently upgraded my graphics card from a GeForce GTX 1070 to a Radeon RX 6700. On my old graphics card I WoW almost never lagged my whole PC, but now it seems to lag all the time.
Granted I did increase the graphics settings, but not enough that it should cause this. It always lags heavily during loading screens and oddly sometimes when I tab out and then cover the WoW window with a different window it also lags. If it’s not covered by another window it doesn’t happen as often when I’m tabbed out. Also happens randomly at other times.
I also got a new SSD and did a fresh install of Windows 10 and (as far as I know) all the necessary drivers. The only thing I could possibly think is the reason is the fact that I’m using an HDMI cord in the monitor plugged into an HDMI to DisplayPort adapter, but that doesn’t seem like it should be lagging my entire PC or my other monitor. Other than that I have no idea what could be causing this lag.
I had a similar issue happen when I upgraded to an AMD card as well. It turned out to be that the game wasn’t pushing the GPU hard enough and it was leading into aggressive downclocking. The simple solution that fixed it for me was to make a custom profile where I manually set the min and max frequencies. I set the max to the normal max of the GPU and then I set the min to a couple hundred MHz below that(needs a little wiggle room). The goal isn’t to overclock the card, but to simply keep the clocks high. You can set that as the global profile (kind of a tiny waste of power) or you can manually set that profile to each game you need it in by adding the game to the list and picking the profile.
With Nvidia GPUs, they made it much easier to deal with this issue. You’d just set the power profile to “prefer max power” in the NV control panel, which does the same thing of keeping the clocks high. AMD doesn’t seem to have a similar quick setting like that, which is a bummer.
BEWARE: If you plan on using my method, make 100% sure to do it right and I’m not responsible for any accidental damages you might sustain, in the event of overclocking it too far on accident. Granted, the AMD software does a pretty good job of not letting you go wildly out of the normal bounds.