120hz TV won't do 120hz...

Wonderclam

Honorable
Jul 24, 2012
15
0
10,560
so, I just bought a new 60" Samsung LED Smart TV that has 120hz refresh rate. It replaced my old 40" LCD.

I mainly use the TV as an output from my videocard's HDMI. I watch netflix, read forums, youtube, etc.. on it. I switch the videocard output between the new TV and my Asus 24" gaming monitor. I have an EVGA GTX 970 videocard.

When I open up the Nvidia control panel to change the refresh rate on the new TV, it doesn't have the option to go higher than 60 hz. What gives? My gamin monitor can do 144hz.

The TV specifically says it's 120hz.
 

Wonderclam

Honorable
Jul 24, 2012
15
0
10,560
I got a couple more questions, guys.

The TV only has 2 HDMI ports and 1 composite port and they're hard to get to in the back of the TV.

If I buy an HDMI extension, plug it in in the back and run it to the front, that way I can just plug in the device I want easily on the extension cable, would there be quality loss because of the extension cable? Same with the composite extension. Would there be a quality loss?
 

jossrik

Distinguished
Sep 26, 2002
81
0
18,610
120Hz TV and 120Hz monitor are different. Most TVs have 120Hz "engines" while only having 60Hz panels for display. The computer inside the TV ups the framerate to 120Hz for a clearer picture, while the output stays at 60Hz, you can't run it any higher than that. There are TVs out there that claim 960Hz or better, but be warned, chances are, you'll only get 60Hz out of the panel. From what I hear, there are TVs that can display 120Hz true. I have never personally seen one. Granted, I'm not a Guru, but that's my two cents.
 
120 Hz exists on TVs for one reason - showing film conversions without judder. Most of them cannot accept a 120 Hz external signal.

Most film movies were shot at 24 fps (well, 23.976 fps, but most TVs just display them at 24 fps resulting in a fractionally shorter runtime). If you try to display it on a 60 Hz TV, there's no integer conversion. You have to alternate. You show the first film frame for 2 TV frames, the second film frame for 3 TV frames, the third film frame for 2 TV frames, etc. This jumping between 2-3-2-3-etc frames causes a herky-jerky effect called judder. Smooth panning shots appear to stutter. An object moving across the screen at constant velocity appears to rapidly speed up and slow down.

Frame interpolation (which causes the dreaded soap opera effect) is one way to solve this problem. The TV interpolates in between the film frames, and displays 60 different frames per second. The smoothness of the resulting picture looks like video instead of film, which is why it's called the soap opera effect.

120 Hz TVs are the other way to solve the problem. If the TV displays 120 fps internally, then they can just display every film frame for 5 TV frames without any judder. No soap opera effect, and smooth pans and motion remains smooth.