AMD R9 285 in Early 2009 Mac Pro 4,1

Discussion in 'Mac Pro' started by MyNameIsNicola, Mar 22, 2015.

  1. MyNameIsNicola macrumors newbie

    Joined:
    Mar 22, 2015
    Location:
    Cambridge, United Kingdom
    #1
    I bought one of these http://www.amazon.co.uk/gp/product/B00N8THK8K (which is listed as UEFI compatible, requiring a 150W 8-pin power draw) to replace the stock Radeon HD 4870 that came inside my Early 2009 Mac Pro 4,1.

    I've read that the R9 285 is supported in recent OS X versions, but I'm not even getting as far as booting OS X or Windows from what I can tell.

    It fits okay, all cabled up etc, but no happy POST bong or boot of any kind.

    My default boot partition is actually my Windows 7 Bootcamp, so it usually boots that if there is no keyboard intervention, but nothing happens other than fans and HDDs spinning up.

    The HDDs are just spinning; they don't sound like they're being read during boot, so it's not that the machine is booting but I'm just not seeing anything.

    I realise this card is not flashed with Mac specific firmware, but the card is listed as UEFI compatible, and regardless of that, my understanding the worst would be that I would just be missing is the ability to see boot screens?

    Is this card simply too power hungry? Am I doing something stupid?
     
  2. Pressure macrumors 68040

    Pressure

    Joined:
    May 30, 2006
    Location:
    Denmark
    #2
    UEFI is not the same as EFI.

    It should boot to Windows though.
     
  3. MacVidCards Suspended

    Joined:
    Nov 17, 2008
    Location:
    Hollywood, CA
    #3
    Where did you see 285 working in OS X?

    What did you do about 8 pin? They are rarely "optional" especially on the more power-hungry AMD cards.
     
  4. DougTheImpaler macrumors 6502a

    Joined:
    Feb 28, 2006
    Location:
    Central Illinois
    #4
    R9 285 is the same GPU as the R9 M295X, according to this:

    http://www.notebookcheck.net/AMD-Radeon-R9-M295X.129043.0.html

    Tonga is the codename. That's the higher-end GPU available for the 5K iMac, so in theory it COULD be supported. But, of course, AMD support is never that straightforward - my first foray into AMD on my cMP was with an XFX R9 270X, which would never boot. I popped the GT120 into slot 2 and saw that it would start to boot but get stuck (for an hour, I let it sit) as it tried to boot. Yanked the AMD card and it booted straight away. I was reading on Netkas's forum that certain brands of AMD cards (XFX and Sapphire in particular) had issues booting in Macs unless they were flashed. Some AMD cards require hacks to add device IDs to the drivers since they don't include all of them like nVidia's drivers do.

    To troubleshoot, if you have a Mac EFI card, put it in slot 2 to see if it'll try to boot and what the boot screen might look like.
     
  5. Pressure macrumors 68040

    Pressure

    Joined:
    May 30, 2006
    Location:
    Denmark
    #5
    They are technically based on the same chip but the Radeon HD 285 isn't a full Tonga chip as the one found in the iMac 5K.
     
  6. MacVidCards Suspended

    Joined:
    Nov 17, 2008
    Location:
    Hollywood, CA
    #6
    With AMD it is all about device id.

    The 7850 and 7870 have same GPU chip, but 7850 isn't in driver so it doesn't work while 7870 works fine. (it shares same chip and device id of the D500)

    If it isn't in the driver, it won't work. Period.

    You can sometimes PUT it in the driver, but now that means kext dev mode. And for cards that have no real Mac version, there is no "personality" assigned so you have to run as generic card.

    So, unless you actually have a link to someone claiming it runs, it doesn't run.

    Anyone can buy one and let us know what happens.
     
  7. DougTheImpaler macrumors 6502a

    Joined:
    Feb 28, 2006
    Location:
    Central Illinois
    #7

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