Before WoD I've mainly been in 10 man guilds and thus lag wasn't really a problem. However with the Mythic content (20 man) and HC/Flex one (up to 30 man) I often experience massive lag.
Now if I disable all add-ons the lag stops but I'm using a lot of them... so the raiding experience isn't optimal without add-ons.
My question is: Is there a way to find out which add-on is causing this lag?