|I can tell you that I have the same setup in terms of a DVI video card to an HDMI TV and i've had no problem playing games on my Panasonic 50inch.|
The first thing would be to make sure your video card software is up to date.
See if the refresh rate of your TV (from your PC) is set to 60hz.
For ATI: open Catalyst CC, in the Advanced view, click Display Manager, you should then see two monitors. Desktop 1 and Desktop 2. On Desktop 2, make sure it's your Samsung. Click on Desktop 2 and see what the refresh rate is and set it to 60 Hz.
For nVidia: No clue because I don't have nVidia.
AMD Phenom II X2 550 @ 3.11
Patriot PC2-6400 4Gig
Seagate 160Gig SATA
Seagate 320Gig SATA