I would also recommend, before you splash out the new motherboard, verifying that 4770Ks graphics drivers "play nice" at 4K on your monitor.
I had not end of trouble trying to get an old Intel G45 chipset to work with HD-DVD i.e. Would never stay in-sync with the audio - I gave up eventually.
Anandtech's Forums tend to have a lot more experienced contributors who maybe able to clarify.
Good Luck