wow talk about derailing the thread looking at math and physical size.
It is unlikely you will ever need more than 8gb in a gaming PC.
whilst it is nice to say "I have 12gb" or "I have 16gb" of ram. it is in almost all case's wasted if your only doing gaming and a bit of light video editing.
if you where doing some pretty serious video editing, or graphics work then yes more ram would be better for you. However if this was the case you would probably be speaking to someone in regards to getting a custom PC built for that reason and not asking on a gaming site