So, you bought a new 4k TV and the salesperson is trying to
sell you new whizbang goochi goochi 4k, or Ultra HDMI, or HDMI-2
cables to handle the new high speeds. Do not listen. It is a
scam to increase store profit.
It is important to understand that HDMI cables are pipes, just
like water pipes. Liquid goes in liquid comes out. The pipe does
not care whether it is water or soda or rum. In HDMI cables,
data goes in and data comes out. No decisions are made, nothing
is done to the data, it simply passes through the cable. The
cable does not care what type of data it is.
A quote from HDMI.org: "Version 2.0 of the HDMI Specification
does not define new cables or new connectors. Current High
Speed cables (category 2 cables) are capable of carrying the
increased bandwidth."
By definition, HDMI supports standard, enhanced, or
high-definition video, plus multi-channel digital audio on a
single cable. There have been two HDMI cable standards, standard
and high speed. Standard HDMI cables have been out of date since
about 2010, but still support devices up to 1080. High speed
cables support everything, including 4k, etc. They do not care
whether the signal is standard, HDR, 4K, ULTRA, HDMI1, or HDMI2.
HDMI cables are marked on the package and on the cable, so just
avoid cables marked "standard" and you will be fine for 4K.
Gold ends, fancy cord wrapping, etc., are pretty, but not
important for delivering signals to the TV. Manufacturing
quality may have some slight affect and might not last long if
abused. Of course, when was the last time you abused your
cables. You plug them in, hide them behind the TV and forget
about them.
The difference in cable quality does matter when you buy longer
lengths. Usually HDMI cables are less than about 9 feet in
length. If you want to string a 50 foot HDMI cable to a
different part of the house, then quality is important, so the
signal is not lost along the length. It still has nothing to do
HDR, 4K, etc., it is simply manufacturing quality and potential
signal loss.
Incidentally, there is a new standard coming out toward the end
of 2017 called HDBaseT. The HDBaseT cable combines audio and
video signals, USB, network, and even power into one single
cable and is set to replace HDMI in the long run. It will be in
the next generation devices, but that will likely take years.