3106b3: Coherence still does not work on dual monitor

Discussion in 'Parallels Desktop for Mac' started by engyew, Dec 29, 2006.

  1. engyew

    engyew Member

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    39
    I can confirm that full screen to the secondary monitor works again for me on a dual monitor set up. Yeah!!!!!


    However, Coherence still does not work. When I go into Coherence mode Parallels just disappears from my screens. I can see the Windows Apps in the dock but when I click on them, nothing happens.

    I tried: I unplugged my second monitor, switched into Coherence mode and it works. I can see my app (Firefox). I plug in my second monitor and it disappears.

    I tried: I have my two monitors connected. Start Parallels on primary monitor, click Coherence and it disappears. Unplug one, and its there

    So methinks Coherence is not working on dual screen. I am using a MacBook if that helps. Might be the graphics card.
     
  2. inferno10

    inferno10 Bit poster

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    Quick question. There is an option under Edit->Virtual Machine->Coherence called 'Use multiple displays'. Did you check this option?
     
  3. engyew

    engyew Member

    Messages:
    39
    Yes. I did.

    OK. I can confirm that Coherence with dual monitor works with ONE of my VM. The basic one with only Windows XP/ Office and Live Messenger installed.

    However my primary VM with my work and all will not switch into Coherence. I did a compare of all configurations and to a large extend (like working directory etc.) they are identical.

    The only major difference is that my primary VM has been upgraded repeatedly since I first strated using Parallels, my basic VM I just created one month ago.

    Ugh. Do I have to rebuild my VM from scratch?
     
  4. coumerelli

    coumerelli Bit poster

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    6
    I think it's a problem with the independant resolutions on the separate monitors. with my MB set to 1280x800 and the secondary set to 1280x960 coherence doesn't work. However if I set both of them to the same (1024x768, in this case) then, yep - coherence works. So, can we not have separate monitor resolutions? And the windows only 'sees' one monitor so maximizing windows floods the entire viewing area - also not a pleasent result. I hope this is resolved in the final release. By the way, I'm only doing this with Windows 2000. I should be installing XP and Server 2003 on here in the next couple of days.
     
  5. coumerelli

    coumerelli Bit poster

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    I have to retract SOME of what I previously posted - while it didn't work with my Windows 2000 install on Parallels, it seems to work just fine with XP Pro. Either screen; and the start menu is on only one screen. It looks great! (for Windows, that is).
     
  6. coumerelli

    coumerelli Bit poster

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    OK. I've figured it out (Ben, are you reading this? -- though you might already know)...

    Using RC2 Build 3106...

    IF 'Use multiple displays' is checked then coherence does not work if the monitors are set to different resolutions - this goes for W2K SP4 and XP SP2.

    IF 'Use multiple displays' is NOT checked then coherance works on one of the monitors as is should. Effectively, I suppose, the virtual OS thinks that there is only 1 monitor.

    I think that's it. I'm not editing older posts so that this thread would be bumped. Request to make this sticky.

    Correct me anywhere I'm wrong. Thanks.

    Mike
     
  7. mayb2

    mayb2 Bit poster

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    I have been trying to get this to work and this thread has helped ... however it seems that it will not work if the resolution is 1920x1200

    I lowered the resolution down from there on both monitors and it works great. So, 1920x1200 is an issue that needs to be fixed?
     
  8. mayb2

    mayb2 Bit poster

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    3
    Sorry forgot to add Iam using the latest beta 3170
     
  9. itsdapead

    itsdapead Hunter

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    177
    Coherence and multiple monitors...

    Works fine for me - both in XP and 2000 (even together, which is pretty impressive...!)

    Build 3150, Mac Pro, standard NVidia 7300

    Monitor 1 : 1680x1050
    Monitor 2: 1280x1024

    ...although (for reasons that should be obvious) you really need to reposition the windows task bar to the left or right edge, rather than the bottom, of the screen.

    Just a thought: have you tried increasing the video RAM setting in the VM configuration (its under Memory, not Video)?
     
  10. mayb2

    mayb2 Bit poster

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    You da man... Increased the Video Memory and it works beautiful!!... Thanks so much
     
  11. itsdapead

    itsdapead Hunter

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    Moral of the story...

    If you look into the display control panel in windows you'll see that, in coherence mode, windows sees one huge screen covering both your monitors. (I think coherence works by "masking out" the unused areas of the screen so that the mac desktop shows through).
    .
    Lets say you have one 20" iMac with a 1650x1080 screen plus a nice 23" 1900x1200 model. Now windows will see a single screen that (ignoring the small change for the menu bar) is (1650+1900)x1200 - now, at 32 bit colour (4 bytes per pixel) I make that 16.25MB just for the screen buffer. Have two 23" displays and that goes up to about 18MB.

    The default video RAM allocation in Parallels is 16MB.
    QED.
     

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