Problem with 120hz in New Samsung with Mac Mini setup

Discussion in 'Apple TV and Home Theater' started by apatel87, Jul 25, 2010.

  1. apatel87 macrumors regular

    Mar 30, 2009
    Hi, I searched Mroogle and I wasnt able to find anything on the topic. I bought a new Samsung LN40C630 with 120 hz and I seem to be having some problems. When I connected the tv and went to System prefs > display, the highest refresh rate that I get is 60 Hz. I dont have any problems if I set my clear but when i leave it on standard i getthe soap opera effect but with some juddering. When I turn my tv on I always get the display that says 60 hz. Would this discrepancy be causing my problems with the juddering. I am not sure if this is due to the movies, the mac mini, or the TV. Any suggestions. WHy doesnt my tv indicate 120 hz when i turn it on? Why does it say 60 hz. Sorry for all the questions. Any help is much appreciated
  2. wywern209 macrumors 65832


    Sep 7, 2008
    do you rly want to know?
    I don't exactly have an answer to your question but you could try setting the refresh rate on your TV to 60hz. the reason why your mac doesn't support 120hz is because computer monitors don't support that yet. more over. i don't think this is going to change. 60hz is here to stay on 2d monitors. i think 3d will require 120hz but i think 3d is a gimmick.
  3. apatel87 thread starter macrumors regular

    Mar 30, 2009
    Hmmm thats interesting. Maybe I am missing something important but then what is the point of having a 120hz tv. I know its important for live broadcasting but isnt there a need in movies too, like action movies? I am not sure why mac mini would not support 120hz output then
  4. Yvan256 macrumors 601


    Jul 5, 2004
    Your Mac mini is probably set to output at 60 Hz, which is why your TV is saying 60 Hz too.

    My Mac mini is connected to a ViewSonic VP171s, running in 1280x1024 at 75 Hz. Go in System preferences / Displays to see if you can change the refresh rate to 120 Hz. If your Mac mini detected your TV correctly, maybe 120 Hz will be available in the list.

    Then again, maybe not. In my list I see 56, 60, 67, 70, 72, 73, 75 and 85 Hz but my choices are limited to 60 or 75 Hz, the others are greyed out. Maybe your Mac mini is choosing 60 Hz because 60 Hz * 2 matches 120 Hz perfectly, any other choice would not sync up evenly.
  5. brentsg macrumors 68040

    Oct 15, 2008
    120Hz on your display is a marketing gimmick. That LCD cannot accept anything higher than 60Hz. It's got some internal circuitry that will create half of the frames to come up with 120.

    Obviously you can't perfectly create content that wasn't in the original source, so that accounts for the soap opera look and artifacts that you see.
  6. roidy macrumors 65816

    Dec 30, 2008
    Nottingham, UK
    As brentsg says, it's a gimmik, all the TV does is take your 60Hz signal and extrapolates the missing frames. As far as I know no TV accepts a signal at greater than the maximum broadcast rate of 60Hz.
  7. trip1ex macrumors 68000

    Jan 10, 2008
    120hz is not a gimmick. It reduces motion blur. Noticeably.

    Input source won't be greater than 60hz though.
  8. eponym macrumors 6502

    Jul 2, 2010
    120Hz is not a gimmick, but it is pointless for anything other than 24fps movies. Which is why TVs let you turn it on/off based on the input.

    The over simplified explanation:

    Film = 24 frames per second
    60Hz divided by 24 = 2.5

    Notice it doesn't evenly divide? This means compromises are made to the picture and it suffers from motion blur/judder.

    TV = 30fps
    60Hz / 30fps = 2. :) Nice and even. Looks smooth.

    Now if we used 120 for both:

    120Hz/24 = 5
    120Hz/30 = 4

    ^ Now both divide evenly and there's no compromised frames. And then because each frame is on screen for multiple refreshes, the TV can use its own software to further improve (subjective) the picture by modifying some of those refreshes to almost make new frames. This can make it look unnatural and is totally a user preference ("Clear" mode just shows the nice even frames, no further enhancement).
  9. roidy macrumors 65816

    Dec 30, 2008
    Nottingham, UK
    Maybe it's not a gimmik and it has it's uses, but it's still extremly bad marketing when a TV says it's 120Hz and you find out that it wont actually accept a 120Hz signal like the OP is just now finding out.
  10. Erendiox macrumors 6502a


    Oct 15, 2004
    Brooklyn NY
    It's the other way around. The mini will not output a 120Hz signal. That's not Samsung's fault. The 120Hz feature is meant primarily for movies and HDTV broadcasting anyway.
  11. roidy macrumors 65816

    Dec 30, 2008
    Nottingham, UK
    Maybe the the mini wont output a 120Hz signal, but that dosn't change the fact that the TV wont even accept a 120Hz signal anyway. This is taken out of the Samsung LN40C630 manual and lists all the modes it supports:-
    Now you look through that list and tell me which mode supports a refresh rate of 120Hz..... None, so yes it's Samsungs fault. They advertise the TV as 120Hz but don't tell you it wont accept a 120Hz signal. Most people know this but the OP didn't and throught the TV would accept a 120Hz signal, therefore bad marketing.
  12. eponym macrumors 6502

    Jul 2, 2010
    "Most people" don't know anything about their HDTVs. I'd wager 99% don't know what the 'p' means in 720p/1080p. Who says consumers think they need a 120 Hz signal to take advantage of it? Nobody ever says they's always marketed as "it makes your movies look better"—which it does.

    Regardless of source frequency, it's still a 120 Hz TV anyway. I don't think you really understand what that means...120 wasn't simply chosen because of marketing BS or because it's conveniently 2x 60Hz (i.e. twice as good!). It's a technical choice because of it being a common multiple of both 24 and 30/60 (interlaced TV, like a 1080i HD cable signal is 30fps split into odd and even lines—making it 60Hz).

    The screen is refreshing 120 times per second. That doesn't change depending on the source. If your Mini is outputting a 60Hz signal, the TV simply displays each refresh from the computer twice.

    There aren't any 120 Hz video sources to support because they don't exist outside of computers directly generating that.
  13. roidy macrumors 65816

    Dec 30, 2008
    Nottingham, UK
    It's not about thinking you need a 120Hz signal to take advantage of it. It's about the OP expecting to be able to input a 120Hz signal into a TV that says 120Hz on the box.

    Yes it's a 120Hz TV that just wont accept a 120Hz signal, which is what it seems the OP expected it to be able to do. You've got to see how it could be confusing to some people.

    I know exactly what that means. But that dosn't stop people being mislead into buying a TV that says 120Hz on it and thinking "Oh, I'll be able to hook up my PC/MAC and use a 120Hz refresh rate"

    Your assuming that people only use there TV's for movies/video. I for one have my PC gaming rig connected to my HDTV where a higher refresh rate is preferred.

    The fact still remains the OP purchased a TV that says 120Hz on the box expecting to be able to input signals with that refresh rate.

    Now your just insulting people.
  14. MowingDevil macrumors 68000


    Jul 30, 2008
    Vancouver, BC & Sydney, NSW
    My Samsung TV is 240hz and I was disappointed to find it was actually causing artefacts on blu-ray movies. Turns out I have to turn it off to get rid of the problem. The 240hz is optimized for sports HDTV and video games, basically when there is a fast moving camera following a ball or puck. You can see the difference as there is less blurring as the picture pans. So unless I'm watching sports I'm basically running this TV at 60hz and to be honest its just fine.
  15. apatel87 thread starter macrumors regular

    Mar 30, 2009
    Wow, thanks everyone for all the insight. I thought I knew a bit about TVs before I bought one but now it seems as if I didn't. So basically, I am not going to get 120 hz of the TV because the TV can't handle 120hz? I am not sure then why Samsung would say that their TVs are 120hz. Is this the case for all 120Hz tvs?
    If I have a high def cable box do I need to do anything to display that in 120hz? I guess now I am confused more than before. If anyone has this TV what settings do you use to watch your content?
    Would a bluray player change the output or does the output just not matter? If anyone can just break it down for me that would be really helpful.
    Also, is anyone familar with the Samsung's automotion settings? If I put it on standard i get the soap opera effect with the slight juddering. If I put it on clear it doesnt do that. Does that mean that the 120hz is not on?
  16. brentsg macrumors 68040

    Oct 15, 2008
    I owned one, hated it, got rid of it.

    It reduces sample and hold blur at the expense of adding artifacts. No thanks..

    Yeah I understand that it's good with 5:5 pulldown, which in my view is a more legit utilization of the technology. But honestly most people have had their 24fps movies displayed at 30fps for so long that they don't even notice the techline judder anyways.
  17. mchalebk macrumors 6502a

    Feb 4, 2008
    It's important to note that 120 Hz or 240 Hz is the refresh rate of the LCD panel. They keep going to higher and higher refresh rates to combat motion blur. This does not inherently have anything to do with the motion processing / frame insertion technology that is made possible by having a higher refresh rate.

    It's also worth noting that having a 120 Hz LCD TV does not necessarily mean it can do 5:5 pulldown for 24 Hz material. This may not be true for sets today, but 2 years ago (when I was researching TVs), many 120 Hz sets did not offer true 5:5 pulldown.

    If anyone really wants to get into this further, I'd recommend checking out the LCD Flat Panel Displays Forum at AVS Forum:
  18. trip1ex macrumors 68000

    Jan 10, 2008
    Refresh rate and frame rate are 2 different things.
  19. macpro2000 macrumors 6502a

    Apr 20, 2005
    Important concept to understand.
  20. Sorensenp macrumors newbie

    Jul 27, 2010
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  21. killerjoon macrumors newbie

    Aug 2, 2009
    HDMI (LN40C630) to DVI (Mac, Apple Computer) setting problem

    I have a Mac pro computer and a new Samsung LN40C630 TV. I hooked up my computer to the TV using a DVI to HDMI cable and I'm not getting great results. Initially the Mac Pro set the image for overscan. If I turn off overscan the image is quite a bit smaller than it should be on screen. Is there a trick to getting this to work?
  22. peterjcat macrumors 6502

    Jun 14, 2010
    You need to leave overscan ON on the Mac, and then turn it OFF on the TV (using dot-by-dot, "just", 1:1 or some similarly named mode).

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