The exact reason why the new client lags for many people (Verified reason, Riot read please)

The chat. As strange as it may look, the chat is the main source of lag in the client. To partially fix this, search for random text in the friends search bar so that no friends show up and you'll see a big improvement to performance. I hope Riot will read this message and look for what of the chat is exactly causing the lag. Probably it's because all the friends are rendering even when outside of the window
Report as:
Offensive Spam Harassment Incorrect Board