4k man...

Hi people, I stepped into it. A client gave me a Samsung QLED 43 inch TV to use as a monitor for "fixing" his zip drive problem (he had it slaved to a ROM drive so it wasn't working properly). One tax audit survival later, TV... Anyway, I want to take advantage and run a higher res. Currently it's running at 1920x1080. I've tried a variety of thing to change the res but none were really successful. The card can run higher resolution than that. The card is a Radeon HD 6450 with 2G DDR3 with a max res of 2560 x 1600 at 60 Hz. I tried using pclos's ui but it doesn't seem to be working. I'm assuming I'm doing something wrong (obviously) so here I am. Any thoughts humans, AIs and others? Kate