YouTube Causing UI System Lag

[Tucom]

It was so bizarre - there's only one channel I've come across on YouTube that does this. Basically once clicking on this channel (GameRiot) - everything runs considerably slower and lag arises; YouTube red page loading progress bar chugs at a lower frame rate, and switching between full screen apps using my TrackPad 2 sometimes freezes completely.

This is the channel - https://www.youtube.com/user/GameRiotArmy

Does this happen for anyone else? Running a year old 2015 Retina 4K iMac Core i5 3.2Ghz SSD and Iris Pro GPU.

 

[Samuelsan2001]

It was so bizarre - there's only one channel I've come across on YouTube that does this. Basically once clicking on this channel (GameRiot) - everything runs considerably slower and lag arises; YouTube red page loading progress bar chugs at a lower frame rate, and switching between full screen apps using my TrackPad 2 sometimes freezes completely.

This is the channel - https://www.youtube.com/user/GameRiotArmy

Does this happen for anyone else? Running a year old 2015 Retina 4K iMac Core i5 3.2Ghz SSD and Iris Pro GPU.

It's fine on my iPad.

 

[Tucom]

It's fine on my iPad.

Not iPad - iMac, or any Mac running El Cap.

UPDATE - Seems to be a Safari-only thing; runs totally fine on Google Chrome. Really weird, literally causes the whole Aqua UI to lock up and freeze for moments at a time.

 

[BigJohno]

Youtube on Safari has always been crap. Hope something changes with Sierra.

 

[maflynn]

It does seem a little laggy on my iMac (and safari), I recommend using chrome for this channel, if the performance is too frustrating

 

[miffytherabbit]

Weirdly this happened to me today too. It only happened on the GameSpot Youtube channel (I was watching a review). I tried to go full screen and the whole thing locked up for about five seconds. It started again suddenly, but every time I toggled the page to full screen and back it locked up. I was so worried about that I ran a diagnostics check, but it came back fine. It's even stranger coming across your post today, as I'd never even heard of this issue before, let alone experienced it myself.