Hello! This is my first post ever!
I heard that some people have had performance issues after BFA released, so i decided to share some of my tricks on how i got rid of (most) of my performance problems.
1. LOADING SCREEN BEING SLOW
Adding this to your config:
SET worldPreloadNonCritical “0”
or typing the following ingame:
/console worldPreloadNonCritical 0
seems to make the loading screen time alot shorter.
2. M2FASTER
Use at your own risk!
First find out how many Cores your PC has, to do that simply go to
Task-Manager → Performance - click on “CPU”
and check your Core amount.
Depending on your Core amount, you need to type following:
2 Core
/console M2faster 1
4 Core
/console M2faster 3
6 Core
/console M2faster 5
8 Core
/console M2faster 7
i think you got the hang of it, just take your core amount and subtract it with 1.
3. OVERHEATING
This doesnt really fit to performance but i feel like it belongs here.
If your pc reaches temperatures you are not comfortable with then just
Cap your FPS using the Max FPS Slider in your Systems Tab or use V-SYNC
(you may get some Input Lag with V-SYNC)
you can also use MSI Afterburner to set your Fan Speed on Auto or Manual.
AMD Users also have the “Chill” feature, it pretty much manages your PC to be as silent and as cool as possible (may affect your performance 
).
4. UNSTABLE FPS
If you experience micro stuttering it may be because your fps keep jumping from a high amount to a low amount.
Simply capping your FPS to your Refresh Rate or maybe going 1-5FPS higher seems to fix the stutter by ALOT (for me atleast)
You can also try to cap different FPS amounts by checking which one is the smoothest for you.
For me it’s 81 and 76.
5. ABILITY DELAY
Was a big topic in Legion, but people forgot about it.
/dump GetCVar(“SpellQueueWindow”)
to get your current SpellQueWindow (lag tolerance)
/console SpellQueueWindow x
Instead of the X you can type your
current MS (ping)
or
0 to have no SpellQueWindow
6. SOUND
If you prefer your own music over the game sounds then you can just disable all sounds in the Sounds Tab.
I heard it boosts your FPS and fixes some stuttering
7. MOUSE JUMPS TO THE MIDDLE
This doesnt really fit to performance but i feel like it belongs here.
Everyone knows and hates this.
Adding
SET rawMouseEnable “1”
SET rawMouseAccelerationEnable “0”
to your config will eliminate it.
But if thats not the case then keep reading!
I found another fix.
If your mouse has its own software to change it’s settings then
Lower the Refresh Rate to around 125-250hz
Yes, your mouse will be pretty choppy but you can
adjust the DPI to make it better.
8. FULLSCREEN OPTIMIZATION
Go to your WOW folder, right click the Wow.exe file (not the launcher) and disable Fullscreen Optimization
It might fix some problems.
9. BASICS
Blizzard’s favorite response
Use The Repair Tool in your Launcher
or
Delete WTF, Cache & Interface
or
Disable some Addons which may cause lags
It might do wonders for you!
PROGRAMS TO BOOST FPS
-Advanced Systemcare
-Razer Game Booster
That’s it folks, i hope this guide helped!