4K 60fps Youtube

You have fast Internet connection and you think you can play some UHD 4K from Youtube with no problem.  Wrong.

I don't have the very specifics but I can't really play Youtube 4K on my Mac in most or all cases I tried.  (I know I should say all cases but let's keep it not scientific)*

The video just stutters.  It has nothing to do with my connection speed.

I think it's because Youtube uses the V9 codec or something something that Apple doesn't support.

If you run the Safari browser it doesn't even try, the video just gives you 1080p as the best option.  When uses Chrome, it lets you play with 2160p with stutter every 2 seconds or so.  1440p is fine though.

So that's the state of Youtube 4K on a Mac.

I no longer have any "convenient" access to a PC to test it out.

*The only uploader whose 4k video can play smoothly is Filmic Box, so I don't understand, I don't think they lie as the Settings does show it's 4K 2160p.  So I don't understand.  But all else plays stuttering.  This only applies to using the Chrome browser; Safari still falls back to 1080p and doesn't bother with 4K not even try.

update:  I think using Chrome on Mac, I can play 2160p (probably at 30fps) but it stutters at 2160p60fps.

update: I got the chance to play 2160p60fps on my 2012 MBP and it plays flawlessly.  So I stand corrected.  It "must" be something else.  I was playing it on a 2008 MACPRO3,1 with the GTX 770 GPU, the rig isn't meant to be running the latest greatest OS X so this defect of playing the 2160p60fps maybe a small price to pay.  Safari does still lower the playback to 1080p60fps.