Boot Config file edit lines (MAKE SURE THE TWO LINES BELOW ARE AT THE TOP OF THE NOTEPAD):
gfx-enable-gfx-jobs=1
gfx-enable-native-gfx-jobs=1
TO HAVE VALHEIM ALWAYS START ON HIGH PRIORITY:
On Windows you can create a shortcut of the valheim.exe to your desktop. Then right click, click Settings then change the path/target from:
YOUR-GAME-PATH\valheim.exe
to
cmd.exe /c start "Valheim" /high "YOUR-GAME-PATH\valheim.exe"
Now just use the shortcut to start.
*Credit to u/RustyB3ans and u/DerBoeseWolf on Reddit for these tips.