reading avsforum.com is downright depressing
Ignore that quote, most of it is nonsense and the rest is irrelevant. First of all, it doesn't matter that "there is no official 4k delivery system for consumer content at the moment" because we're not talking about consumer content (i.e. movies and TV), but about hooking up a PC. Secondly, while it's true that HDMI 2.0 cannot support "4k AND 8k up to 120fps", we don't need that right now - all we're looking to get is 4K@60Hz with full color resolution, which HDMI 2.0
is capable of. The claim that "making a true 4:4:4 panel and electronics requires a lot of bandwidth and complexity" is also irrelevant; the current panels support 4:4:4 just fine, this was never a problem when they were running at 30Hz.
At this point we are dealing with firmware bugs in the TV and/or video card. It may be difficult to resolve and I expect quite a bit of finger-pointing between Samsung and Nvidia, but it's not a structural defect of HDMI 2.0 or the 4K TV panels themselves.
FWIW, if you want to try a premium HDMI cable, I'd recommend one of the
Belden-derived products from Blue Jeans Cable. This is the only HDMI cable where I've actually heard a sensible description of
why the reliability and signal transmission is improved over standard designs. These have been on the market for a couple of years.