Lag during 25 boss fight

help, i got lag during 25 boss fight (icc, ulduar, voa, etc)
its so irritated, i hear on discord my guild already finish the boss but im still stick with the boss fight
i ping to logon server, its fine
and i also using pingzapper its not working either
I JUST WANDERING, IF ANY SETTING TO REDUCE LAG?
#ripenglish
#stayhome

Yes, get a better connection and a better PC. Turn down particle effect in settings, turn down weather effect and use /console spellEffectlevel 1