Why did YouTube begin to lag on a NOT weak PC?

Question

YouTube

YouTube has never lagged before, I'm used to watching everything in Full HD at 2x speed. Now if I set 2x speed in Full HD it is on the video of various let's players, where there is 60fps, it starts to lag. At the same time, the computer is Xeon e5-2689, 16GB of memory in four streams, vidyuha rx5700. I play rdr2 at max almost full HD 70+- fps. And YouTube lags, it’s funny and incomprehensible) I think to demolish Windows, but still, suddenly there is a solution, or at least an explanation of this unpleasant situation. Also, the video card runs all the benches with a bang.
ps restarting the PC seems to heal, but not always and for a while. I thought I had some kind of miner, but it seems that if I don’t mine and don’t play, I don’t hear the load on the VC and its heating

Answer 1

For starters, of course, just put another browser with a clean profile (extensions can create problems) and look there.
Well, the easiest way to check if the hardware is the cause is to turn on playback on a clean OS, find a way and a place for a temporary installation, not necessarily windows, but with linux you can’t put the driver on the livecd version, i.e. you still need to install it on a disk / flash drive
ps How exactly does the video lag? Is the smoothness of playback interrupted by periodic bursts or a constantly small number of frames (a dozen for example)?

Answer 2

try launching youtube from a different browser. there is also the option that you installed AdBlock, I had this. when I removed the adblock, everything worked fine