Mac Pro Dual Video Cards (one for windows, one for osx)

Discussion in 'Mac Pro' started by Chone, Jul 22, 2008.

  1. Chone macrumors 65816

    Chone

    Joined:
    Aug 11, 2006
    #1
    Can you use a regular card (such as a HD 4870/GTX 280) for Windows and still have OSX recognize the 7300GT that came with the mac pro without the need for swapping or removing the cards?

    If so, what do I need to achieve this?

    Thanks.
     
  2. italiano40 macrumors 65816

    italiano40

    Joined:
    Oct 7, 2007
    Location:
    NY
    #2
    I don't think you can do that, both video cards will be seen by both windows and Mac OSX
     
  3. jamesi macrumors 6502a

    jamesi

    Joined:
    Sep 13, 2005
    Location:
    Davis CA
    #3
    my understanding is that the 7300GT will be recognized in OS X and windows while a 4870 would only be seen in windows. only video cards that are produced for mac will be recognized in OS X, so it wont be able to see that new GTX 260 you were thinking about. but windows will see these fine
     
  4. Chone thread starter macrumors 65816

    Chone

    Joined:
    Aug 11, 2006
    #4
    That's pretty much my intent, I want a new gaming card for my Mac Pro but I only game in Windows so I only really need the card to work in Windows but since there is no Mac version of the HD 4870/GTX 260 then I would still need the 7300GT for OSX.

    However, I'm worried about possible issues, I always knew regular cards were recognized in Windows just fine but not on OSX but I don't want to lose it. Last I hear this wasn't possible but now what's really the consensus on this, if I disable the 7300GT on the Windows side will I be fine?

    I hope you guys understand my situation.
     
  5. prograham macrumors member

    prograham

    Joined:
    Jun 9, 2006
    Location:
    New York
    #5
    This is exactly what I want to know as well but there doesn't seem like there's one place where you can read a definitive answer.

    I have a mac pro with a 2600XT that came with it. I'd like to put in an ATI 4870 and use it only for windows (via bootcamp), without having to ever open my mac.

    Does this cause problems?
     
  6. nanofrog macrumors G4

    Joined:
    May 6, 2008
    #6
    Here's proof that it has been done. :)
    Multiple graphics cards can be done, and will operate between OS X and Boot Camp. :D From what I've seen on the forum, most that have had trouble, resulted from inadequate power supplied to the new card. Some use a 6 pin PCIe power cable, others such as the HD4870 use both the 6 pin and a separate 8 pin PCIe power cable. The card comes with both, but the 6 pin won't work. You wind up trying to draw too much power off the same 12V rail (4 pin flat Molex connector).

    You should use a 6 pin to 6 pin cable that attaches to the logic board, along with the 8 pin in the box.

    Hope this helps, and good luck. ;)
     
  7. prograham macrumors member

    prograham

    Joined:
    Jun 9, 2006
    Location:
    New York
    #7
    excellent to see someone has done it and described it just as I would like to have it. That ms for the post! I think I might be buying a 4870 now as soon as I make sure I see where in my mp where the pins fit onto the motherboard.
     
  8. nanofrog macrumors G4

    Joined:
    May 6, 2008
    #8
    The power socket on the motherboard is just left, and slightly above of slot 2, IIRC. ;)
     
  9. Cindori macrumors 68040

    Cindori

    Joined:
    Jan 17, 2008
    Location:
    Sweden
    #9
    If I put a PC card in slot 1 and Mac card in slot 2, booting osx will result in a black screen. Any thoughts??


    Also, if you have a pre 2008 mac pro, the second slot is only 4x instead of 16x, so you will lose alooooot of performance.
     
  10. grue macrumors 65816

    Joined:
    Nov 14, 2003
    Location:
    Somewhere.
    #10
    You can configure it to go like this:

    Slot 4: 8x
    Slot 3: 1x
    Slot 2: 1x
    Slot 1: 16x

    Put the Windows card in Slot 4, et voila. It'll still be a bottleneck, but not nearly as much of one.
     
  11. prograham macrumors member

    prograham

    Joined:
    Jun 9, 2006
    Location:
    New York
    #11
    Well, I bit the bullet and bought an ATI 4870x2. I bought the 6-6 pin power cord and a molex power extention to plug into the 8pin cord. No love from windows.

    I uninstalled the old drivers, booted to vga mode, installed the latest 8.9 driver, but no video will come out of the card. It shows up in device manager as functioning properly, but the catylst control center doesn't list it as an option, it only list the 2600.

    I'm pretty disappointed that there is zero information on how to get these pc-only cards working in a mac pro.

    I guess my pc gaming days are done. I'll probably return it for an xbox 360. It's too bad microsoft can't make a decent OS and Apple can't get a gaming graphics card.

    EDIT: well, no sooner had a i posted than I figured I would give it one last look since nothing was giving me an error. Disabling the 2600 via device manager did the trick. Now, the mac 2600 lcd sits on but black while my other lcd uses the 4870x2 for my windows gaming. Interestingly, booting in windows (the progress boot bar) still comes up on the mac lcd, but then flips over to the other one once windows fully loads. YaY!

    Now I just have to figure out how to unlock the potential of this card, because at a 1600 resolution I was only getting avg. 60fps in unreal tournament 3.

    And by the way, this card - so far (including my hour of gaming) - is whisper quiet. Seriously, I have a library silent apartment and i don't hear it, yet I can hear my 1st gen mac mini from across the room. I hope to "unlock" the card and get it humming.
     
  12. belunos macrumors member

    Joined:
    Aug 10, 2008
    #12
    I don't know if this is the case, but some games are locked not to go above a certain FPS. I'd search around the net and see if this is true for UT3
     
  13. prograham macrumors member

    prograham

    Joined:
    Jun 9, 2006
    Location:
    New York
    #13
    Well, it gets drawn out. One of my cores is disabled. A little googling and you'll see many people - many PC people - with this problemof a "disabled adapter" in the ati 4870x2. I have yet to find a solution to it. I might be returning this card after all and just settle for a mac 3870.

    Or get an xbox, I just don't enjoy messing with hardware anymore and if ATI can't provide drivers to at least have a fully functioning card then it's not worth for me.
     
  14. prograham macrumors member

    prograham

    Joined:
    Jun 9, 2006
    Location:
    New York
    #14
    Vista... whodathunkit

    Well, installing Vista really worked wonders.

    Not only did it list both adapters for the 4870x2 as enabled (well, a primary and an enabled), it also started using my ATI 2600HD card!

    You see, I have a Mac Pro and was using the 4870x2 through bootcamp. I have one monitor plugged into the 2600HD (which came with my mac), and one into the 4870x2.

    In XP, once I had the 4870x2 going (with only one core working), my 2600 monitor would be "on" with a grey screen, but unusable. In Vista, I can do extended desktop. It's really quite amazing, it's the first thing I've seen windows do that the Mac won't - use two different video cards for extended desktop.

    In any case, now I am getting performance from both cores for my games under windows and am very happy.

    I'll ask you all about the AI Overdrive soon, because I don't think I am doing it right or something, but that's for another day.

    Thanks to all for the help!!

    Brad

    EDIT:
    What I am not happy about is ATI's support. I had opened a ticket about this problem and they informed me that it was "normal behavior" for the second adapter to be listed as disabled if a monitor was not plugged into it. THIS IS BLANTANTLY FALSE. It was not using the second GPU. Now, in Vista, -without a second monitor plugged in-, the second adapter is listed as "enabled".
    I feel bad for anyone that doesn't know much about computers, because if they had received this kind of support i'm sure they would have assumed it to be working since there was no real "error" reporting anywhere.
    Shame ATI, shame.
     
  15. sibbz macrumors newbie

    Joined:
    Aug 7, 2010
    #15
    i'm going this route:

    7300 for booting osx
    ATI 4890 for gaming in windows....

    boot windows from the 7300, and replug when windows desktop appears.. no flashing needed, just the replug :)

    (windows will boot to black screen when the 4890 is in, no idea why)

    good luck :)
     
  16. Mackilroy macrumors 68040

    Mackilroy

    Joined:
    Jun 29, 2006
    #16
    This topic is two years old. ;)

    You might as well flash it, I ran a 4890 as the sole GPU in my Mac Pro for months. No unplugging necessary.
     

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