My CPU Performance shoots way up when playing chess? Why?

I notice the cpu usage shoots highest when advertising is being downloaded into the page, when it's done, I can move the pcs much better. But downloading a simple banner ad shouldn't eat up resources. I think this is spyware bot related.

Hi, I have an older system, win XP, Pentium 4 dual core, fast internet 100gbps, GT 710 gpu, and yet when I log in to chess.com and start playing chess, my cpu shoots up to 95 to 100% !! It's difficult to move the chess pcs, because they get a little "stuck" because my computer is bottlenecked. Any ideas would be highly appreciated. btw, after I log out from chess.com my cpu goes down to 0%. I don't have any active running programs.
Just please don't tell me that you also do your banking on that PC...

Hi, I have an older system, win XP, Pentium 4 dual core, fast internet 100gbps, GT 710 gpu, and yet when I log in to chess.com and start playing chess, my cpu shoots up to 95 to 100% !! It's difficult to move the chess pcs, because they get a little "stuck" because my computer is bottlenecked. Any ideas would be highly appreciated. btw, after I log out from chess.com my cpu goes down to 0%. I don't have any active running programs.
Probably an ad causing it or a memory leak in the browser.

The OP has posted about this before: https://www.chess.com/forum/view/community/chess-com-spyware-infestation
Maybe he's looking for different suggestions? Although, in the first thread, we didn't know he was running XP. Running Windows XP on the internet is hugely vulnerable to malware. @OP, if you can't get a new Windows machine, you might want to consider putting a lightweight distro of Linux on your Pentium PC.
I actually have an extra old Windows XP machine with only 1 GB of RAM. I installed a lightweight Linux distro on it so I could use it on the internet. Even so, when I fire up Firefox on it, the browser is extremely sluggish. I really should upgrade to 2 GB of RAM (lol), but since I hardly ever use the machine, it hasn't been a high priority.
Hi, I have an older system, win XP, Pentium 4 dual core, fast internet 100gbps, GT 710 gpu, and yet when I log in to chess.com and start playing chess, my cpu shoots up to 95 to 100% !! It's difficult to move the chess pcs, because they get a little "stuck" because my computer is bottlenecked. Any ideas would be highly appreciated. btw, after I log out from chess.com my cpu goes down to 0%. I don't have any active running programs.