LCD 75Hz refresh rate

Discussion in 'Displays' started by nicoliani, Oct 26, 2007.

  1. nicoliani

    nicoliani n00bie

    Messages:
    46
    Joined:
    Sep 2, 2007
    LCD's are standard 60Hz refresh rate. But you can increase it to 75Hz to get better image quality in games.
    What I wonder is if the increase will have a negative impact on the monitors input lag? If it takes e.g. 40ms for the image to show up at 60Hz will it now take e.g. 70ms?

    Besides DVI is cut at 60Hz. Anything above 60Hz it have to send the image twice like 50Hz+25Hz.
    What the standard of the DVI for 60Hz does it send the image at 60Hz or does it go by 30Hz+30Hz?
     
  2. ToastyX

    ToastyX [H]ard|Gawd

    Messages:
    1,390
    Joined:
    Mar 12, 2005
    DVI is not limited to 60 Hz. DVI can handle any refresh rate as long as it fits within the bandwidth.

    The problem is most LCD monitors don't support 75 Hz properly. Most will still output only 60 frames per second by skipping every 5th frame. The only LCD monitor I've seen that doesn't do that is the Samsung 226BW. There are probably others, but I haven't seen any myself.

    Raising the refresh rate should not have a negative impact on lag. It should actually reduce lag if it works properly.
     
  3. nicoliani

    nicoliani n00bie

    Messages:
    46
    Joined:
    Sep 2, 2007
  4. ToastyX

    ToastyX [H]ard|Gawd

    Messages:
    1,390
    Joined:
    Mar 12, 2005
    That article doesn't mention the 226BW anywhere.
     
  5. nicoliani

    nicoliani n00bie

    Messages:
    46
    Joined:
    Sep 2, 2007
    It was in another article, I can't remember where.
    You said skipping every 5th frame, how is this noticed in games?

    In the link I posted in the in there in the last page they are talking about 100Hz and input lag. This was 2006 and they just noticed input lag. What the writer tries to say is that the 100Hz TV they tested produced an input lag around 40ms. And if I get it right he refers that because of the 100Hz. But all LCD's have a natural input lag because of technical limitations, and a screen that is 24' it's very normal that the input lag lands on 40ms or even higher no matter if it's displayed at 65Hz or 100Hz.
     
  6. ToastyX

    ToastyX [H]ard|Gawd

    Messages:
    1,390
    Joined:
    Mar 12, 2005
    That's not the same. Those 100 Hz HDTVs aren't really 100 Hz. They're 50 Hz with intermediate frames added by an image processor. The image processing along with overdrive adds lag. It really shouldn't lag that much, but Samsung displays with S-PVA panels tend to lag more than they should.

    The monitors that skip every 5th frame at 75 Hz actually receive 75 frames per second but only display 60 of them. That makes motion appear jittery. It's very noticeable to me just by moving the mouse. It's also easy to see with scrolling text.
     
  7. nicoliani

    nicoliani n00bie

    Messages:
    46
    Joined:
    Sep 2, 2007
    It looks bad with 75Hz for Windows. In ATI CP I have an option so 75Hz is triggered when an 3D application is started like a a game. In games the image quality gets impressive compared to 60Hz but still the text gets little blurish but not annoying.

    Will there come computer LCD's with higher standards than the 60Hz?
     
  8. Nielo TM

    Nielo TM Gawd

    Messages:
    958
    Joined:
    Aug 27, 2006
    100/120Hz LCDs are actually refreshing at that rate. Otherwise motion compensation wouldn’t work.
     
  9. Nielo TM

    Nielo TM Gawd

    Messages:
    958
    Joined:
    Aug 27, 2006
  10. Nielo TM

    Nielo TM Gawd

    Messages:
    958
    Joined:
    Aug 27, 2006
    Standard LCDs display each for 16.6ms. The lag is however is caused by pixel response time and other elements that drives the LCD.

    DVI supports multiple refresh rates and resolutions (but, 1920 x 1200-60Hz is the limit for single-link DVI). The problem however lies in the display device.

    PS: It would be more helpful if manufactures take PAL countries into account before locking the monitors at 60Hz.
     
  11. SoAndSo

    SoAndSo [H]ard|Gawd

    Messages:
    1,236
    Joined:
    Oct 2, 2007

    how do i do that? ive tried looking throught the CP but i cant see any way how to

    PM me with the answer please as i know ill forget to look here again :>
     
  12. Nielo TM

    Nielo TM Gawd

    Messages:
    958
    Joined:
    Aug 27, 2006
    Go to manual/custom timing on nvidia control panel. Then add a profile. When a pop-up appears, enter the resolution (1680 x 1050), refresh rate (75Hz) and color (32bit). Then click on test and click on OK.

    Click on the profile you’ve just created and click on apply. If that doesn’t work, you can select 75Hz on the windows display property under advanced.
     
  13. buffbiff21

    buffbiff21 Gawd

    Messages:
    1,014
    Joined:
    Sep 27, 2006
    With active matrix LCDs it's not going to matter.

    Maybe with something like DVDs, since 24 doesn't go into 60 evenly, there's going to be some minute screen tearing. Or if you like to see more of your mouse cursor when you move it quickly across the screen.

    But still. Refresh rates over 60hz on LCDs are just pointless.
     
  14. lillimon04

    lillimon04 2[H]4U

    Messages:
    3,762
    Joined:
    Oct 24, 2006
    I run my 940mw at 75hz and it looks perfect. But you can only do it after windows does an update for the monitor, or if you get the new drivers for the monitor by yourself.
     
  15. nicoliani

    nicoliani n00bie

    Messages:
    46
    Joined:
    Sep 2, 2007
    Or maybe 2009?
     
  16. shurcooL

    shurcooL [H]ard|Gawd

    Messages:
    1,125
    Joined:
    Oct 12, 2007
    Of course it matters. With higher refresh rates, you could turn on V-Sync in games and enjoy higher FPS without the tearing of frames (as it happens with V-Sync off).
     
  17. nicoliani

    nicoliani n00bie

    Messages:
    46
    Joined:
    Sep 2, 2007
    I've been told that v-sync adds input lag.
     
  18. nicoliani

    nicoliani n00bie

    Messages:
    46
    Joined:
    Sep 2, 2007
    Just got a mail from a manufacture, where I asked if they soon would ship 100Hz monitors. The answer not in the year to come, no plans.
     
  19. LawGiver

    LawGiver 2[H]4U

    Messages:
    2,054
    Joined:
    Oct 16, 2005
    well my vx922 does in fact operate @ 75hz. I know this because in any game that is not fps locked, TF2 for example, when I set vcync ON, it never go above 75 fps if I set refresh rate to 75hz. likewise it will never go above 60 fps if I set refresh rate to 60hz.
     
  20. ryan_975

    ryan_975 [H]ardForum Junkie

    Messages:
    13,858
    Joined:
    Feb 6, 2006
    Just because it accepts a 75hz signal from the graphics card doesn't mean that the monitor is actually displaying all 75 frames. For instance, my 20.1" can accept 75hz, my games will run at 75FPS when I have Vsync on, but if I bring up the menu on my monitor it'll still say 60Hz