Large vs Small 4k video playback

[NameBrandHipster]

Long story short, VLC seems unable to play large feature length 4k videos, but does fine with small 4k videos, like online samples.

I've been perusing this issue for months, I've tried every setting combination known to man, and I only get 15fps, and with the settings that achieve that the video playback quality of other videos is drastically reduced. So no good.
(and it's not a hardware issue either, I'm running a gaming pc that plays Crisis @ 50fps, max settings.)

I've sense given up, and now have a new question, mostly directed at the devs.

Is this a feature that you are working towards? 4k video support on par with something like DivX Player?
I don't mind using DivX, but I'd much rather use VideoLAN sense I have it on my external drive which I bring around to watch movies on. (plus VLC is just sweet)

Is it even possible for VLC to support such large 4k videos in the future?

Any insight would be appreciated.

Thanks guys! Keep up the awesome work.