3870 Mac Edition + 3870X2 = Crossfire?

Discussion in 'Mac Pro' started by ungraphic, Apr 27, 2009.

  1. ungraphic macrumors 6502a

    ungraphic

    Joined:
    Nov 15, 2007
    Location:
    Toronto, Canada
    #1
    Would a Radeon 3870 Mac Edition be compatible with a PC purchased 3870x2 for crossfire under windows? I've heard that standard 3870s for PC (such as the Sapphire) are recognized in OS X and Windows when paired with a Mac Edition 3870. I can buy a 3870 Mac Edition for a good price, but am curious if I opted for an X2 on top of my single 3870 would give any significant improvements over two Mac Edition 3870s paired together? And more importantly, would it work? Also, is the Mac Pros (2007) PSU enough to power a 3870x2 and a 3870 at once?

    Thanks!
     
  2. Rankrotten macrumors 6502

    Rankrotten

    Joined:
    Sep 12, 2006
    Location:
    UK
    #2
    Yes they work together in crossfire under windows, I'm running the same setup on an '06 Mac Pro
     
  3. ungraphic thread starter macrumors 6502a

    ungraphic

    Joined:
    Nov 15, 2007
    Location:
    Toronto, Canada
    #3
    Any issues? Heat? Noise? Power?

    I assume you have the Mac Edition 3870 in SLOT 1, and the 3870x2 in slots 2 and 3, correct?
     
  4. Rankrotten macrumors 6502

    Rankrotten

    Joined:
    Sep 12, 2006
    Location:
    UK
    #4
    Yes that's correct. I used expansion slot utility on my '06 Mac Pro to make each lane x8, your computer may be newer with two x16 slots but it matters little in windows when crossfired.

    Each card is fed from the motherboard pcie power connector and the x2 has an additional power feed coming from the lower drive bay to the end connector on the card. No issues with this.

    It is fairly noisy in OS X but virtually silent in windows. OS X has no fan control for the x2 (yet..)
     
  5. ungraphic thread starter macrumors 6502a

    ungraphic

    Joined:
    Nov 15, 2007
    Location:
    Toronto, Canada
    #5
    The 3870x2 would cost me about double over the 3870 Mac Edition. Think the performance boost is worth the extra price tag?
     
  6. Rankrotten macrumors 6502

    Rankrotten

    Joined:
    Sep 12, 2006
    Location:
    UK
    #6
    Well only you can answer that..

    For what it's worth I purchased it when it was the top line ATI card but now the single 4870 is just as fast and cheaper than the 3870x2, plus the 4870 can be flashed into a mac card. There are reports of the 4870x2 working on Mac OS X (one core) if you want to go for a one card solution.

    If you can pick up a cheap 3870x2 then go for it but don't spend lots of money on what basically is last year's card.
     
  7. ungraphic thread starter macrumors 6502a

    ungraphic

    Joined:
    Nov 15, 2007
    Location:
    Toronto, Canada
    #7
    Good point. I think i'll drop just $100 on a single 3870. Price is fair and will give me the performance boost I need for HL2 EP2. Thanks for your input! :)
     
  8. Pressure macrumors 68040

    Pressure

    Joined:
    May 30, 2006
    Location:
    Denmark
    #8
    Even the Radeon HD 4850 is faster than the Radeon HD 3870x2 ;)
     

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