My two cents:

1) Ardell does have a point - but I'm using now-modest 2006 hardware
with Ubuntu Studio in Full HD (1920*1080).
I think that I even had it run in Full HD using the integrated video
card, before I happened to acquire a second-hand then-good separate
one.

2) I'm repeatedly experiencing a fall-back from 1920*1080 to 1280*768
with my 2009 powerhouse (running Windows).
It takes some shifting from one connector to another and similar
"no-ops" to have it eventually re-recognize the Full HD.