Mac Pro 2 videocards double GPU ?

Discussion in 'Mac Pro' started by FrankDoorhof, Oct 8, 2008.

  1. FrankDoorhof macrumors newbie

    Oct 8, 2008
    I recently switched from PC to Mac and bought a Mac Pro 8 core (and MBP).

    Most of the time I use photoshop/aperture and FCP.
    Internal memory is 10GB (4 more will be added in the future).

    Today I ordered the new ATI 4870 512MB card to speed up CS4 and Aperture when CS4 is released.

    I have a small question however, should I replace the original ATI or leave it in, I will connect the two monitors to the new card.

    If I leave the old card in will it combine the two GPUs ?
    The original card is also the ATI.

  2. Tallest Skil macrumors P6

    Tallest Skil

    Aug 13, 2006
    1 Geostationary Tower Plaza
    Combine? Only if you have two ATI cards and only in Windows and only with a CrossFire bridge.

    And the card won't work at all in OS X. You won't get to use those monitors there. You can only use seven cards in OS X in the Mac Pro.

    7300, X1900, Quadro 4500, HD 2600, 8800 GT, 3870, and Quadro 5600.
  3. FrankDoorhof thread starter macrumors newbie

    Oct 8, 2008
    The 4870 is a true Mac card.
    I hardly use windows anymore :D

    The idea I had is that maybe MAC Os would use the extra GPU from the old ATI to get extra performance.
    I know in the PC world we use the Crossfire but I have no idea how MAC Os works in that aspect, also when looking online there is little information.

    The reason I have this idea is that you can buy the MacPro new with 3 videocards, I can't imagine that they would run 6 monitors but I can imagine that the GPUs of those cards are combined for more speed.

    But I could be totally wrong of course, that's why I posted the question.
  4. Tallest Skil macrumors P6

    Tallest Skil

    Aug 13, 2006
    1 Geostationary Tower Plaza
    No... ATI doesn't make drivers for it. So it won't work. And OS X doesn't combine GPU power. The only purpose is to drive extra displays, but that won't even work in OS X with that card.
  5. FrankDoorhof thread starter macrumors newbie

    Oct 8, 2008
    3870 of course (sorry, bit late and been busy today :D)

    I will than replace the original card, thanks for the answer (and quick it was :D)
  6. Tallest Skil macrumors P6

    Tallest Skil

    Aug 13, 2006
    1 Geostationary Tower Plaza
    AHA! Okay, you'll really want to at least KEEP the original card, as the OS X install disk doesn't have the drivers for the 3870. If you have a problem and need to reinstall, you won't be able to boot with only the 3870 in.
  7. FrankDoorhof thread starter macrumors newbie

    Oct 8, 2008
    Ah that's a good one, never thought about that.
    Will keep it now for sure.
  8. Shownarou macrumors regular

    Sep 15, 2008
    Newton, IA
    If you leave the original card in, you can run four monitors.. There's really no reason to take it out.
  9. Exman macrumors member

    Oct 6, 2008
    Are you running a hacked BIOS on that card to get it working on OS X? I see no reference to 3870 on the Apple website.

    There is also no crossfire or SLi support on a Mac, especially a Mac Pro. You'd really need an Intel Skulltrail to run 8-core + Crossfire + Sli, but I don't think anyone has successfully run OS X on this yet.
  10. Sun Baked macrumors G5

    Sun Baked

    May 19, 2002
    Actually running all those displays is the reason you can buy the machine with all those video cards.

    Some of the workstations do indeed have to power multimedia kiosks or data displays for these users.


    Snow leopard may take advantage of the GPUs of the cards for some of the routines, but this won't equal more FPS -- more like faster rendering of a motion picture or of some of the graphics filters. We shall see when the next generation of Apple Pro apps ship to take advantage of Snow Leopard.
  11. gotzero macrumors 68040

    Jan 6, 2007
    Mid-Atlantic, US
    I have two 2600s installed in mine to use four monitors. They are more or less completely independent. Everything works fantastically though.
  12. FrankDoorhof thread starter macrumors newbie

    Oct 8, 2008
    Google for ATI HD3870 Mac.
    It's a new card for the Mac, there is a Mac and PC version, we ordered the Mac version.

    I don't play games, the only things I do are Photoshop, Aperture and FCP.
    Especially photoshop CS4 and Aperture should be quicker with the faster GPU as I understand.
  13. Kosh66 macrumors 6502

    Jul 15, 2004
    Apple doesn't seem to sell it on the Store. The ATI HD3870 is a ATI retail Mac/PC card, you'll find it on the ATI/AMD site.
  14. nanofrog macrumors G4

    May 6, 2008
    The ATI 3870 Mac & PC ed. can be found at for $217.99USD. :)
  15. highjumppudding macrumors 6502


    Mar 1, 2008
    if you have 2 cards that means you can connect up to 4 video outs, to monitors or a tv, etc. other than that, if you are running dual monitor and you are a pro user you can run the spare monitor from the second card so that you are not running both monitors on a single card (splitting/sharing the memory between the monitors). so if you connect the monitors to different cards youll have greater performance.
  16. FrankDoorhof thread starter macrumors newbie

    Oct 8, 2008
    My second monitor is used for Email, MSN and the tools from photoshop and the keywords from Aperture.

    If I share them between the two cards will photoshop not slow down because one of the monitors is driven by a lesser card ?

    I can't find anything on the managment MacOsX does for this kind of situations, for safe keepings I think I will just run the 3870.
  17. Delameko macrumors member

    May 1, 2008
    As my question is related to this one, I thought I'd avoid creating a new thread...

    If I did SLI/Crossfire two cards for use in gaming on Windows, would they still operate fine in OSX? I wouldn't have to remove the SLI connection for OSX or anything? Worth kowing for sure before splashing out for a second card.

    Is SLI/Crossfire support for Mac in the hands of Apple or ATI/NVidia and their driver writers?
  18. xraydoc macrumors demi-god


    Oct 9, 2005
    Nvidia's SLI does not work in the Mac Pros (under Windows) in any way. The Intel chipset does not support it at all.

    ATI's Crossfire, I believe, will work correctly (again, Windows only) for certain cards, though I don't know if it'll work for all of them.
  19. Delameko macrumors member

    May 1, 2008
    Thanks for the info. Maybe I won't bother.

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