High CPU usage during game

I can't be the only one. I can't even hear music during play. And loosing games because the interface is lagging/barely responsible.
First I thought it is a browser issue, but now it is happening in ff and in chrome as well.
Everything is ok while an actual game starts, than bam cpu usage on 95%.
What the hell causes this?

How do I reproduce this? What OS? Do I have to be playing a game or does observing a game causing the same issue?

@koga545hun

Ok, your computer does not have a big amount of space on the hard drive and motherboard so, in result one of your fans may not be working properly and your computer heats up very fast. Now, depending on the game and speed your CPU usage can be high, so this is a result of it heating up and bam you might start hearing noises coming from the computer.

Now, this is only speculation based on what happened to me on another computer, so it might not be the case and the cause may not even be that serious.

Regards,

I once made the mistake of having three concurrent games on lichess. This made my computer lag really badly and the whole experience very unpleasant.

I routinely run things eating a lot of my CPU without it hurting browser responsiveness as much as having three lichess games at the same time did.

So lichess is definitely doing something during games that eats CPU. Maybe it's related to anti-cheat ?

Thanks for everyone answering. It was that fking chess clock bar! I turned it off, and everything is fine.

The high cpu usage happened even watching games, but not in the main screen, so I suspected the clock and bingo. No lag no fan noise. Thank God it's over, it was sooo annoying.

By the way maybe the code of that bar needs some review.

God bless everyone! :)