Two graphic cards in early 2008 mac pro

Discussion in 'Mac Pro' started by fno, Apr 25, 2010.

  1. fno macrumors newbie

    Joined:
    Apr 25, 2010
    #1
    Hi.

    I have a Mac Pro (early 2008) with a standard graphic card (ATI Radeo). I need to run 3 monitors so I just bought a new graphic card, a NVIDIA GeForce GT 120, which is the standard card in the newer mac pro's. Unfortunately there seem to be a conflict between the cards. I have tried different PCI slots, different monitor schemes etc, but I can't get it to work reliably.

    Maybe the old card just "died" at the same time I got the new one... here's the situation:

    I left the old card in slot 1 and installed the new one in slot 3 (I know now it should have been slot 2 because of the speed).
    First it worked, I had all three monitors working but after some reboots, the monitors on my old card didn't work anymore. I tried zapping the P-ram, and it worked again for some time. Now it seems completely not working. I have tried to change PCI slots but still, the original card does not work.
    I can see it in the monitors control panels "arrange" pafge and in the system profiler it also comes up, stating there's a monitor connected. However neither the name of the card nor the name of the monitor is displayed.

    I have tried to take out the new card and re-install the old one in slot 1 (as from the factory) but there's still no signal in the monitor.

    Has it died? Has some conflict between the cards "messed it up"? (sorry, I have very little technical knowledge).

    If I buy a new GeForce identical to the one I have, will they be able to work side-by-side or will there be a conflict?

    Thanks in advance for your help.
    :confused:
    Flemming
     
  2. Hellhammer Moderator

    Hellhammer

    Staff Member

    Joined:
    Dec 10, 2008
    Location:
    Finland
    #2
    Sounds like it has. Have you tried it alone (take the GT120 off) and then booting and see if it works?

    Dual GT 120s should work as long as you put them in PCIe 2.0 slots
     
  3. iamcheerful macrumors 6502

    iamcheerful

    Joined:
    Oct 3, 2008
    #3
    fno/Flemming has done that.
     
  4. Hellhammer Moderator

    Hellhammer

    Staff Member

    Joined:
    Dec 10, 2008
    Location:
    Finland
    #4
    Oh, I should go back to elementary school and learn how to read :p

    Anyway, that sounds even more a failed GPU now
     
  5. iamcheerful macrumors 6502

    iamcheerful

    Joined:
    Oct 3, 2008
    #5
    nah Hellhammer, when i was reading TS's issue. i was wondering the same thing myself (if he'd tried the factory setting). but i was thinking TS should be pretty experience and no reason for him/her not to test the original working configuration, thus, i re-read the post several times!

    couldn't think of what he/she has not done thus didn't reply.

    so you see, i'll have to join you in elementary school and pay more attention to what i read. ;)

    most of the time we're simply too eager to assist users that we tend to overlook some details.
     
  6. fno thread starter macrumors newbie

    Joined:
    Apr 25, 2010
    #6
    Hi guys,


    Thanks for your quick replies :)

    Just to prove that I'm a complete technical morron, please enlighten me:

    Is the GPU situated on the graphic card or is it a part of the motherboard?

    So two GT 120's should work, but are the PCI slots in my machine PCIe 2.0's? Or how can I check that?

    Thanks!
    Flemming
     
  7. iamcheerful macrumors 6502

    iamcheerful

    Joined:
    Oct 3, 2008
    #7
  8. Hellhammer Moderator

    Hellhammer

    Staff Member

    Joined:
    Dec 10, 2008
    Location:
    Finland
    #8
    GPU is the graphics card. In Mac Pro, it's a separate card which can be upgraded while in other Macs, it's integrated or very hard to upgrade.

    You Mac Pro has two PCIe 2.0 x16 slots and two PCIe x4 slots. You must use the x16 for GT120.
     
  9. fno thread starter macrumors newbie

    Joined:
    Apr 25, 2010
    #9
    Thanks a lot! I will order a new card then...

    :) F
     
  10. iamcheerful macrumors 6502

    iamcheerful

    Joined:
    Oct 3, 2008
    #10
    It is not a must, but if you want the maximum performance, you should use the x16 slot as Hellhammer suggested.
     
  11. Dark Dragoon macrumors 6502a

    Dark Dragoon

    Joined:
    Jul 28, 2006
    Location:
    UK
    #11
    It isn't necessary to use the x16 slots, the card should work fine in the 4x slots as well, it will just be bottlenecked a bit.

    The preferred situation is to use the two 16x slots and then use the 4x slots if you need to add more cards.

    EDIT: iamcheerful, got there before me.
     
  12. Hellhammer Moderator

    Hellhammer

    Staff Member

    Joined:
    Dec 10, 2008
    Location:
    Finland
    #12
    Yeah, I should have phrased it differently but as OP has a free x16 slot, he should use it :cool:
     
  13. iamcheerful macrumors 6502

    iamcheerful

    Joined:
    Oct 3, 2008
    #13
    fno, you see you're in good hands. so many of us just replying at almost the same time. thank goodness MRF can handle the load. :D

    good luck with your new card(s)!
     

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