6870 only working on 2 of my 3 displays no matter what combo I try

Discussion in 'Mac Pro' started by NOD, Oct 9, 2011.

  1. NOD macrumors member

    Joined:
    Jul 20, 2008
    #1
    :mad::mad::mad:

    So I installed this 6870 on my Mac Pro 3,1 tonight, and I have 3 displays (two 24-inch Gateways and a 42-inch Westinghouse monitor). In the past, I was just using 2 8800GT's.

    Well, after installing it and trying to use the HDMI port, the Display Port, and one of the DVI ports, I found that, whether I was in windows 7 (64-bit) or Lion 10.7.1, only 2 of the 3 displays will show the desktop, no matter what combination I use.

    I've tried fiddling in both System Preferences (Lion) and in the Display Settings (Win7) and, no matter what, when I add a 3rd display, 1 of the other 2 displays goes blank. I've tried every combination of DVI x 2, DP, and HDMI, and it happens every time, in both OS's.

    I will give 1 bazillion Internet Legend Points to anyone who can solve my apparent idiocy.:confused:
     
  2. Cindori macrumors 68040

    Cindori

    Joined:
    Jan 17, 2008
    Location:
    Sweden
    #2
    to use three displays with an ati 6000 card, one of them must be connected to the DP port. if the display is using DVI and you are connecting through a dvi-dp adapter, the adapter needs to be active. active adapters are generally a bit more expensive, ranging from $25-40 as opposed to the passive $9 adapters.

    in Lion you might have a bit more fiddling to do, or it might just not work since drivers are not fully compatible yet. so when you troubleshoot, start in windows. make sure you download ati drivers too.
     
  3. NOD thread starter macrumors member

    Joined:
    Jul 20, 2008
    #3
    Thanks for this. Ya know, I thought my DP-to-DVI cable was active, but, after looking where I bought it online, it is in fact passive.

    Ordered a new active adapter online. Will get back on this thread when it shows up to give some closure.

    Thanks again.

    BTW, while I'm being an attention whore, I tried to flash EFI on it (using ATI win flash and Zeus), but got the following error:

    dd: bs must be between 1 and 9223372036854775807
    Traceback (most recent call last):
    File "fixrom.py", line 110, in <module>
    op_rom.fix()
    File "fixrom.py", line 90, in fix
    self.data[-1] = chr(0x100 - sum)
    ValueError: chr() arg not in range(256) (1)



    Any idea as to the origin of this?
     
  4. Cindori macrumors 68040

    Cindori

    Joined:
    Jan 17, 2008
    Location:
    Sweden
    #4
    nah you tried to make firmware... some needs a "128" number instad of "512"... head over to netkas.org for manual instructions
     
  5. NOD thread starter macrumors member

    Joined:
    Jul 20, 2008
    #5
    Will do.

    Thanks again.
     

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