Dual 4870 - What are the odds?

Discussion in 'Mac Pro' started by Wild-Bill, Jul 8, 2008.

  1. Wild-Bill macrumors 68030

    Wild-Bill

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    #1
    Now that ATI seems to be happy to spit out Mac/PC variants of the 3870, what do you think the odds are that we'll see a dual 4870 offered for we few, we happy few with the Mac Pro?? :eek:

    ATI seems to be on a roll lately, and is most definitely engaged in and winning a price war with nVidia. Obviously the 3870 offering is a stab at the nVidia Mac desktop marketshare.

    I would LOVE to have a dual 4870 for my Mac Pro. NATIVE Crossfire in Windows, on one card. Imagine the OpenGL performance on the Mac side as well!!!

    And what if Snow Leopard does capitalize on the spare GPU cycles to increase system-wide performance? Whoa. :D
     
  2. Tallest Skil macrumors P6

    Tallest Skil

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    #2
    0%. The Mac Pro doesn't have the external power adapters required.
     
  3. Wild-Bill thread starter macrumors 68030

    Wild-Bill

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    #3
    Surely they could include needed adapters with the video card. A sort of hybrid that would attach to the PCI-E 4-pin adapter already in there plus another socket to hook up to one of the spare 4-pin adapters in the optical bay. And I'm pretty sure that the dual card wouldn't exceed the Mac Pro's PSU spec.
     
  4. m1stake macrumors 68000

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    #4
    Apple does not use flagship gaming graphics cards like the 4870X2. (Never mind the 6800 Ultra :p)

    On the bright side, the odds are favorable that the 4870 will be offered for the Mac Pro platform at some point in the future (January, at the bare bare bare minimum).
     
  5. Wild-Bill thread starter macrumors 68030

    Wild-Bill

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    #5
    That's what I was referring to. Believe me, I know Apple has no intention of putting it in of their own accord. I was talking about ATI/AMD throwing us another bone in the form of a 4870x2.
     
  6. chewietobbacca macrumors 6502

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    #6
  7. macz1 macrumors 6502

    macz1

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    #7
    The most likely option will be a reference HD 4870. Let's hope the ones which are available now can be flashed later...
     
  8. Pressure macrumors 68040

    Pressure

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    #8
    It's safe to assume that the only graphic card in the Radeon HD 4800 family that would become Mac compatible, would be the Radeon HD 4870.
     
  9. Siron macrumors 6502

    Siron

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    #9
    Pressure
    I believe that the 4870 required two power cables. As the MP has two only what is the maximum wattage that each of those MB connectors can provide? I was wondering if it was possible to rig up a two into one cable (splicing the PCIE ends of two cables to the MB end of another cable). Shouldn't be too difficult if it doesn't overload the single MB connector.
    If the BIOS could be flashed for the Mac then two 3870s in Crossfire mode would be awesome :eek::eek::eek::eek:
     
  10. Siron macrumors 6502

    Siron

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    #10
    Pressure
    I believe that the 4870 required two power cables. As the MP has two only what is the maximum wattage that each of those MB connectors can provide? I was wondering if it was possible to rig up a two into one cable (splicing the PCIE ends of two cables to the MB end of another cable). Shouldn't be too difficult if it doesn't overload the single MB connector.
    If the BIOS could be flashed for the Mac then two 4870s in Crossfire mode would be awesome :eek::eek::eek::eek:
     
  11. kabunaru Guest

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    #11
    Can Crysis finally be conquered/maxed out with Dual ATI Radeon HD 4870s CrossFired? :eek:

    Or will it take 4x 4870 (Quad Crossfire) to finally max out Crysis? :eek::D
     
  12. Spanky Deluxe macrumors 601

    Spanky Deluxe

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    #12
    Probably not. Stupid game if you ask me. Way too demanding on graphics for not that much better graphics than other games.
     
  13. Siron macrumors 6502

    Siron

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    #13
    I agree. The graphics in Half Life 2 are just as good but with half the graphics power. Far Cry 2 will be just as good with less demand on the GPU. Crysis, while a beautiful game from a graphics perspective (with Vista 64 on Very High settings) was badly written as no machine currently available can run it well on its maximum settings.
     
  14. drewx2 macrumors newbie

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  15. macz1 macrumors 6502

    macz1

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    #15
    When I played crysis for the first time I thought wow! that's beautiful. After a while (at the end of the demo) I found it still beautiful to look at but so boring and monotone that I played it never again.

    For this game there has been put so much effort in the graphics that a good story got forgotten.
     
  16. Pressure macrumors 68040

    Pressure

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    #16
    Considering a single Radeon HD 4850 performs nearly as well as two Radeon HD 3870 in CrossfireX or a Radeon HD 3870X2 I have a hard time seeing how it would be awesome ;)

    Other than the fact that it would be EFI compatible.

    I have no idea what a single power cable can provide simply because there are no known specifications on the power supply used in the Mac Pro.
     
  17. Siron macrumors 6502

    Siron

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    #17
    Sorry - I corrected my original post. I meant two 4870s not two 3870s
     
  18. tangles macrumors member

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    #18
    PCIe power requirements...

    I had two 8800GT's in my MacPro (3.0GHz) which worked fine in both OSX, and Vista64. (Ubuntu's X11 config is another story!)

    But now, I have an XFX GTX280 in slot 1 and an one of the 8800GTs in slot 2.

    To do this, I had to rewire one of the supplied 8800GT PCIe power connectors, because they use a smaller, scaled-down version of the 6-pin PCIe cable connector that connects to the MP mobo. I showed my PC buddy who builds PC Audio workstations for a living, and he's never seem them before...
    Gee, thanx Apple for not using standard modular PSU PCIe connectors!! :mad:

    Keeping the scaled-down connector end, (obviously) I wired onto it a 6+2 PCIe connector to drive the GTX280 as it requires (like the new 4870) 1 x 6-pin and also 1x8-pin PCIe power connectors. So both the MP PCIe power connectors coming from the mobo are powering the GTX280.

    This site is an excellent description of the 6+2 PCIe connector that included power diagrams for the 6, 6+2 and 8 pin PCIe Connectors. Infact if you need to make your own "anything" power cable, this site is I keep coming back to...
    http://www.playtool.com/pages/psuconnectors/connectors.html

    Why use a 6+2 pin PCIe power connector and not the 8-pin PCIe connector? Cos now I can revert back to having 2x 6-pin connectors anytime I need to put the 2nd 8800GT back in...

    My rewiring wasn't pretty, but it gets the job done. So much for the MP having a nice cable free mobo feel about it... :rolleyes:

    So, Given that I used up the 2 6-pin cables from the MP's mobo, to get power to the 8800GT, I used the XFX GTX280's supplied 6-pin PCIe to 2-Molex connector and sourced power from the 2 optical molexes that power the optical drives.

    Consequently, I don't have the optical drive connected at the moment, but I want to do more testing before I use a molex splitter.
    Given that the 2 video cards are never used for 3D gaming simultaneously, I'm already confident the MP PSU is coping well with the power requirements. (1200W is what I've read elsewhere!! :eek: )

    So, Assuming no OSX drivers for the 4870. (any word of OSX drivers for the 4870 yet?)
    If one were to install one 4870 in a MP for Windows, some splicing and dicing would be needed (like above) if you wanted to use a 3870/4870 as well for OSX.

    Note: Holding down option to choose what to boot from via EFI is not possible unless I have the 8800GT installed. The GTX280 is not displaying anything on screen when in EFI. and my DELL 24" monitor connected to it, is not aware/powered-up/receiving-signal etc etc ether.
     
  19. Pressure macrumors 68040

    Pressure

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    #19
    Actually, the smaller 6-pin power cable uses a standard connector from Molex.
     
  20. tangles macrumors member

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    #20
    huh?

    Pressure,
    I'm referring to the PCIe connector apple use on their mobo.
    This connector has nothing to do with molex connectors at all.

    Just to clarify:
    Basically apple have used 2 scaled down PCIe 6pin connectors (female) that's soldered directly on the mobo. (scary considering they're 2 12volt rails, on the mobo!!)

    Cheers
     
  21. Spanky Deluxe macrumors 601

    Spanky Deluxe

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    #21
    It *is* a molex connector. Molex is a brand of connector types, not just your standard molex hard drive connector. The standard 6 pin PCIe connector is in fact a "Molex Male Mini-fit Junior" connector while the one on the Apple motherboard is a "Molex Male Micro-fit 3.0" connector.
     

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