model name : Intel(R) Core(TM) i7-6600U CPU @ 2.60GHz
It doesn't have hw acceleration for VC1, so youtube specifically has a lot of issues. I've been able to rectify it by using h264ify to force youtube to give me h264 but a normie isn't going to be able to figure that out.
Even a browser (Chrome and Firefox) tab in the background with a few CSS animations causes it to be noticeably unresponsive in other applications.
It supports 4K output but my tests (backend TypeScript) are measurably slower when the display is at 4K vs 1440p.
What OS are you using? I run Linux so I'm wondering if it's that, but I've tried every different DE and Xorg Vs Wayland and different drivers, and they are all just as bad.
Disclaimer: I bought the Mac for building apps only.
(Ducks)
YouTube is a turd. I do everything I can to avoid using it. How they’ve screwed up a video player that badly boggles the mind.
(Of course, the YouTube frontend is also fairly bloated, which doesn't help. There isn't much of an excuse for that one).