I found out on accident that
/console gxrestart
fixes the pixelated particles bug. I was playing around with the graphics slider going between 1 and 10 and they got stuck all pixelated at 10. I ran that command and it fixed it. You can make a macro out of it if you want and it’s a really quick 1-2 reset.
This fixed it for me as well, but pixels come back after alt-tab.
Yeah, I’ve done a bunch of research since this and found it’s tied to the Windows MPO(multiplane overlay) system that Nvidia and Microsoft both flipped the switch on finally.
“The game will switch to MPO mode when releasing particle effects, and render the particle effects to a render target with smaller resolution to reduce the amount of pixel filling. In addition, in the fierce battle scenes, the release of a large number of particle effects leads to very dramatic changes in the screen, and thus it is difficult for the player to see the details of each frame”
I’m guessing that maybe having background/target fps limit set or maybe the act of alt tabbing causing some kind of frame hitch is triggering the system to do this. Should be resolved soon though.
I hope so, I am STILL having this issue and I have tried everything 
Disable target FPS under the advanced tab and I think you have to set spell density to anything other than dynamic. In my testing, I found this was the only way to avoid having them pixelate out, but it’s been a while so I’m not 100% sure anymore.
Also, after you change those settings, make sure to use the console command /console gxrestart because sometimes changing settings doesn’t kill off the old particles and makes it look like the settings aren’t getting rid of the pixelated effects, so you need to reset them all completely. You can macro it if you want.
just a thought… did anyone reset the recommended settings? like all settings or these settings then adjust them to your liking
I did, I tried everything that has been suggested. I am hoping 9.1 will fix it
Well. I guess I am forever doomed to have pixelated graphics. Today is the big update and they didn’t fix this issue. I bought my computer back in December just for playing WoW with nice graphics and now, I am forever doomed to look like crap.
This fixed mine
Mine is STILL effed. I figured the expansion would help, but no.