LCD Refresh Rate

Discussion in 'Macintosh Computers' started by TyleRomeo, Mar 25, 2005.

  1. TyleRomeo macrumors 6502a

    Joined:
    Mar 22, 2002
    Location:
    New York
    #1
    is there anyway to change the refresh rate of an LCD display. System prefs. under displays don't give me that option. I'm having major issues with my mac mini and a formac gallery lcd display. any 3rd party software or any deeper mac prefs to change the refresh rate.

    tyler
     
  2. Lacero macrumors 604

    Lacero

    Joined:
    Jan 20, 2005
    #2
    LCDs don't have refresh rates. They have what is called pixel latency. The lower the latency of the LCD measured in ms the better the display. If you are getting blurring, or coming fresh from a CRT, moving windows and such will and does look blurry. It is normal. You'll get used to the pixel latency.
     
  3. TyleRomeo thread starter macrumors 6502a

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    Mar 22, 2002
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    New York
    #3
    i get RGB tearing cuase my ati 9200 card in the mini cant handle the formacs 20 inch 1600x1200 res.
     
  4. ravenvii macrumors 604

    ravenvii

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    #4
    Then lower the resolution. There's nothing else you can do.
     
  5. TyleRomeo thread starter macrumors 6502a

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    #5
    its doesnt matter if the res is 640x480 it still tears thru the black levels. There is some sort of refresh but apples display setting doesnt let you overide it.
     
  6. ravenvii macrumors 604

    ravenvii

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    Mar 17, 2004
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    Melenkurion Skyweir
    #6
    As the above posters said, there's no refresh settings for LCDs through the DVI port. And even with VGA, it should be set at 60 Hz. So if you lowered the resolution and still get tearing, there's something wrong with your LCD, the connection, or the video card itself. Dunno what to tell you.
     
  7. TyleRomeo thread starter macrumors 6502a

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    Mar 22, 2002
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    New York
    #7
    the same LCD with DVi works with an ati 9000 card and a nvdia 6800 ultra so its not the display, its the video card, and how do you set it to 60 Hz?
     
  8. andrewfee macrumors 6502

    Joined:
    Aug 29, 2004
    #8
    I think it's a mac thing really, I'm running on a 17" Powerbook with a 128mb ATi Radeon 9700 Mobility and it tears. My old 20" iMac G5 did it too.

    It's a lot less noticable on the Powerbook, but it's still there.

    All LCDs run at 60Hz by default, and (as far as I know) setting the refresh rate higher will damage them, which is why OSX doesn't have a refresh rate setting.
     
  9. TyleRomeo thread starter macrumors 6502a

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    Mar 22, 2002
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    New York
    #9
    wow that sucks, i wonder why the same display didnt tear on the ati 9000 card and neither does my 23 HD cinema. but your 9700 128 does, thats so wrong
     
  10. andrewfee macrumors 6502

    Joined:
    Aug 29, 2004
    #10
    It's very minor, and the animations still look really smooth; no-one else that's used the machine has noticed it, I've just got an eye for these things I guess.

    If anything, I'd say it's running over the 60 (I assume it's 60 and not 30) fps it runs at which is what's causing it, because when I start to open a few more windows it goes away. (and then when I open more still, it appears again)
     
  11. Cracko macrumors newbie

    Joined:
    Apr 6, 2005
    #11
    I have the same problem with my Mac Mini

    I have 2 formacs 2010. I was using it with my powerbook 17 and did not seem to notice anything odd from either Formac. But when using my mac mini I noticed a lot of breakup of video especially when moving the mouse. One of the Formacs does not seem to have the problem but if you look very close it seems to sometimes have very small lines in it. But the other one is quite noticable , I thought I had a bad Mac mini or Formac display. I have been using the Formacs on a PC computer for over a year and have never seen any problem. One thing I noticed that the macs (powerbook or mini) does not display the refresh rate that is being used when hooked to the Formacs. It has a n/a in it. But when I hook a Dell 2405 LCD in dvI mode (1920 x 1200) to the mac mini then it indicates the resolution 1920 x 1200 and also the refresh rate of 60HZ. I have a suspicion that the mac is putting out more than 60HZ. I don't know too much about DVI rates how they compare with the analog.The electronics in the DVI monitor latches the data to the display so it is actually static, but the rate that the computer gives it to it has to be clocked into the monitor to relatch the data or load the data into the display. The main point that makes me think the macs are putting a possible wrong rate to the Formac monitors is that it indicates the rate when I hook up the Dell so it must be able to clock the data at a certain rate to the display. If the data rate to the display is "too fast" then I could see it doing what it is displaying, jumpy data on the display. When I hook the mini to the Dell I don't see any problem. Maybe the Formac is tellling the Mac an incorrect rate to use.

    I was going to do this simple test but I'm kind of concerned that I might damage something. Connect the mini to the Formac and see it act up. Turn the Formac off. Pull the DVI connector from the mini and connect it to the Dell. The Dell reads out the resolution and HZ rate soI can see what the mini is puting out . But it has a resolution of 1920 x 1200 and the Formac is 1600 x1200 so it might auto detect the display and go to the 1920 x 1200.

    I don't know if the Formac can be damaged if overclocked so I'm concerned to keep the Formac attached to the mini or powerbook.

    Anyway if anyone finds a way of setting the mac to a certian rate maybe it can be solved.


    Sorry for the long drawn out message.

    Cracko
     

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