Super User is a question and answer site for computer enthusiasts and power users. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

I just got a Samsung Syncmaster 2233 at a local store, and it's suppose to reach 120 Hz frequencies. I plan on using it with Nvidia 3D vision later on, but I don't have the hardware for that yet. In the mean time, I just want to test the monitor to see if it's working ok.

Obviously, if I set it to 120Hz I can't notice any visual difference compared to 60Hz. So how can I test if the monitor is reaching the higher frequency?


share|improve this question
up vote 0 down vote accepted

Greg's answer regarding the fan got me thinking a little more high-tech:

Your eye can't see the difference, but a camera or video camera can. (Ever tried to use a camera to photograph or film a monitor?) Just look at it through that and compare with a lower rated monitor.

share|improve this answer
Ok, while I didn't have any fans, I do have access to a few cameras in the house. Testing it with my cell phone didn't get any results. When I get around to using an actual video camera I'll comment again. – Malabarba Apr 11 '10 at 15:11
You can easly see the diference. – Hooch Jun 19 '14 at 11:54

Woo Kids hold on a second. The Syncmaster 2233 is an LCD screen NOT a CRT. LCD screens don't have a refresh rate like the old CRT did. The only thing flickering might be the back light at 200Hz or more. 120Hz refers to the input frame rate from the graphics card. The difference between 60 and 120 at desktop might be near impossible to see, the mouse might move a bit smoother.

This screen can display 120 frames per second, so find an old game (like Quake2 or Quake3 Arena) and bring up the frame rate counter from console or use FRAPS and play with the settings (drop the resolution and quality) until you get a constant frame rate over 120FPS. You should feel the difference between when the monitor is at 60Hz and 120Hz.

share|improve this answer
The idea behind it is different but the software forced refresh still happens from top to bottom which looks almost the same as a regular refresh, it is this when people mention Hz with LCD and LED monitors – Timo Huovinen Jul 8 '14 at 15:41

Blink really fast :-P

Actually try putting a fan in front of it. You can definitely tell the difference between 60hz and 120hz using a simple house fan.

share|improve this answer
I see how that might work, unfortunately I have no portable fans in my house. The only ones I've got are ceilling fans. – Malabarba Apr 11 '10 at 15:06
@Dconnors: hang the monitor from the ceiling. lie on your back looking up. tadaah. :) – quack quixote May 13 '10 at 11:20
The Fan trick does not work with LCD unless it has a strobe backlight feature enabled, when it is then you can cleary see it flicker twice as fast in 120Hz mode over 60Hz – Timo Huovinen Jul 9 '14 at 12:42

I've found that scanning my eyes left and right very quickly helps me see any sort of flickering that may be going on. Try futzing with the brightness and contrast if you don't see it at first.

Also, some monitors have a menu item where they show their current display parameters. Of course, if you suspect the monitor then the parameters are probably also suspect.

share|improve this answer
Ok, about the first part: I tried. I really did. And it really didn't get me anywhere. As for the second part: there is indeed a menu item, and if I set the monitor to 120 Hz in Nvidia control panel, than the menu item claims to be at 120 Hz. That's not a definite test, but it is rather comforting. – Malabarba Apr 11 '10 at 15:10

The test I've always heard for CRTs is to stand in front of it, and look 90 degrees to the side, so you can only see the light from the CRT in the very edge of your peripheral vision.

It depends on your vision, but (for example) if I look at a 60-70 Hz signal directly it looks fine, while in my periphery it looks very blinky. (So if I look at 70 Hz for a few hours, my eyes get sore, even though everything looks and feels fine for short periods.) But a 90+ Hz signal looks steady to me at any angle.

This won't tell you if it's 120 Hz exactly, but it could at least indicate that it's running at 100+ Hz.

share|improve this answer

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .