Some feedback on HD5970 in Mac Pro.

Discussion in 'Mac Pro' started by Cocoia, Jul 19, 2010.

  1. macrumors member

    Cocoia

    Joined:
    Jul 19, 2010
    #1
    Hey guys,

    I've been following the news closely, and the threads on custom ROMs, reflashing, etc. I think netkas, cindori and the Rominator and others are doing fantastic work.

    I've got a 2 x 2.8Ghz Quad Mac Pro 3,1 with a 8800GT, 4 hard drives and dual superdrives. I'm considering upgrading it with a 120 GB SSD and a HD5970. Mostly for gaming under Windows; having it work under OS X is not a priority.

    As the current setup with the 8800GT uses one 6-pin PCIe power cable, and a non-OC HD 5970 needs one 6-pin and one 8-pin, I was considering taking the two molex cables from my superdrives (which I don't use) and adapt them (through an adaptor) to an 8-pin to fully power the beast card. The card should take about 3 slots, leaving room for my 8800GT. The PSU should be able to handle the draw from the card. I accept having to switch the monitor on boot / reboot.

    You might have been able to guess, but my main question is this: Am I overlooking things? This way, would a HD5970 work in a 3,1?
     
  2. macrumors 68040

    Cindori

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    #2
    yes. you can probably get one core working under osx without 3d accel (QE)
     
  3. thread starter macrumors member

    Cocoia

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    Jul 19, 2010
    #3
    Thanks. That's awesome icing on the cake. Would I be able to get full speed under Windows OK as well?
     
  4. macrumors 68040

    Cindori

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    #4
    ofc
     
  5. thread starter macrumors member

    Cocoia

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    Jul 19, 2010
    #5
    A little update: the HD5970 is still in transit, and I've ordered an extra 2x 4-pin molex to 8-pin PCIe power cable and a 6-pin Mac Pro motherboard to PCIe 6-pin power cable (30 euros! Christ). I've seen one Macrumors forum poster with some images of his unit running in his 'Pro, so I'm cautiously optimistic now.

    Hopefully all will go well once I've got it installed.
     
  6. macrumors 68040

    Cindori

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    #6
    ----
     
  7. macrumors member

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    Jun 5, 2009
    #7
    I'd be interested to know how you get on, so keep us posted! :)

    I would like to install a 5970 in my Mac Pro 2.1 (3.0, 8 core), but my experience with a 4870 X2 was less than great - windows ran butter smooth for about 15 minutes and then the machine just shut down. I believe Rominator had a similar issue, which if I'm not mistaken, was most likely a lack of power from the MP PSU.

    Does anyone know if the 5970 draws more or less power than a 4870 X2? If it's more I guess I'll just have to go for a 5870 instead. Also, does the MP 3.1 have a better PSU than the 2.1?

    Thanks
     
  8. macrumors 68040

    Cindori

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    #8

    psu is by far not an issue at all.
     
  9. macrumors member

    Joined:
    Jul 21, 2010
    #9
    the 5970 definitely draws more power than a 4xxx series card, same with the 5870, it will draw more power than the 4xxx card as well. and i would actually assume that the power supply may be causing the problem. i know pc's throw in crappy power supplies, and that is a definite main component of a computer and if you go cheap on a power supply that is not a good thing. so id check out what power supply you have, and possibley upgrade that.
     
  10. thread starter macrumors member

    Cocoia

    Joined:
    Jul 19, 2010
    #10
    I'm quite sure a 5970 draws more, as it carries two GPUs on one PCB. Perhaps the issue was how it was powered -- what kind of cables were used?

    Here's the post with the guy running a HD5970 in his (I think) 3,1 unit, by the way. He opted to power it with a 6-pin to 8-pin cable.
     
  11. macrumors member

    Joined:
    Jun 5, 2009
    #11
    The 4870 X2 was also a dual GPU board (2 x 4870 chips in CF I believe). I have been running an XFX 4870 since with no problems.

    I would be very interested to know if you get it running ok (I don't doubt that you will).

    Does anyone know if there are any differences between the 2.1 and 3.1 PSU's?

    I have an 8pin to 6pin adaptor that I have been hanging on to in case I ever upgrade. ;)

    EDIT: When I mentioned the 4970, I meant the 4870 X2. Posts fixed. D'oh!
     
  12. thread starter macrumors member

    Cocoia

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    #12
    What model Mac Pro do you have? How do you power it? 2x6-pin?
     
  13. macrumors member

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    Aug 22, 2008
    #13
    The shutdown is causing by overloading the 12v rails, I encountered it myself. I had my 4870x2 working by getting power from both the motherboard connector and the optical bay molex connectors.
     
  14. macrumors 603

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    #14
    Nothing makes an explosion in Crysis seem quite as real as when the computer makes a loud "CLICK" and completely shuts off at moment of impact. I tried splitting power off Molex and variety of things. In retrospect, I think main issue was the LENGTH of the splitter cables used to make 6 pin into 8 pin.

    I am custom making a Mac Pro 8 pin cable, pix soon.

    The shutoffs frightened me, I was convinced that either a PCB trace or PSU was going to join the tanker truck in Crysis, so I sold the 4870X2. But keeping the power leads as short as possible and using the fattest wire possible would be good ways to get most power into card, rather then heating the cables up.
     
  15. macrumors G5

    jav6454

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    #15
    PSUs make nice fireworks, and have a habbit of taking many other system components with them.

    Which is why I don't recommend nVidia cards, and do NOT recommend the HD5970 (or even the HD5830). HD5970 is not what it is supposed to be. As per nVidia and their GF100 based Fermis, it's not because it's nVidia, it's because of the HIGH POWER DRAW. Simple.
     
  16. macrumors member

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    #16
    It is a 2007 Mac Pro 2.1 (3.0ghz 8 core 'Clovertown'). The 4870 is powered by 2 x 6 pin cables to the mother board. I bought 2 custom made cables off eBay which are thicker than normal.
     
  17. thread starter macrumors member

    Cocoia

    Joined:
    Jul 19, 2010
    #17
    Well, that was super interesting. The HD5970 came with a 2 x 4-pin molex to 8-pin (yay) and I decided to test it in Windows by taking the 6-pin power off my 8800GT and onto the behemoth. Which, by the way, just about fits into the chassis.

    [​IMG]

    With power not yet attached. The midget card below it is the 8800GT.

    In the end I removed the hard drives, CPU heatsink cover and front fan assembly to reroute the optical drive power cables to the midsection -- with the cable running across the top, the case wouldn't shut. There's instructions on doing this in the service manual, which I won't repost here for legal reasons. Easy enough, though.

    Under Windows, the Just Cause 2 benchmarks at 2560x1600, max settings, including AA, where my old card struggled to maintain 16 frames per second, I currently push 50-60. Bad Company 2 is now very playable at 2560x1600 (I had to run it at 1680 before) and Crysis... ah, Crysis. With everything maxed at 2560x1600 (and the real-lifesis mod) it's -barely- playable ;). The card clocks up to full speed, is quite power efficient (45 watt-ish at idle) and runs at 60-65° C after an hour of intensive graphics work. Also super silent! Much more silent than the 8800GT, almost inaudible and a fair bit cooler.

    I don't have my second (super-expensive, Apple-proprietary) 6-pin cable yet so I cannot attest as to how well (or not) it runs with both cards in the Mac Pro. So far it seems the 8800GT doesn't boot with no extra power and if I take a bit of power (a 6-pin) from the HD5970, it revs up its fans to maximum and won't stop. So I've removed it for now. I'll pick up a brand new 6-pin tomorrow and report on how it works.
     
  18. macrumors member

    Joined:
    Jun 5, 2009
    #18
    Very interesting. If it all runs ok after you manage to test it fully, would you fancy doing a guide on what cables were required etc. I am seriously tempted to get one for my MP, and install my old 2600 in a spare slot.

    The only thing I'm not really clear on is feeding power from the optical bay using a molex - never looked in the lower drive bay, so don't really know what goes where and how. ;)

    Keep us updated! :)
     
  19. macrumors 6502

    jhero

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    Not near an Apple Store
    #19
    With the new MP's out, hopefully they price the 5770 at a good price so I can finally replace this 8800gt
     
  20. thread starter macrumors member

    Cocoia

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    Jul 19, 2010
    #20
    I'll do a full rundown on it soon and update the main post -- as soon as I get the extra cable. :)
     
  21. thread starter macrumors member

    Cocoia

    Joined:
    Jul 19, 2010
    #21
    Hmpf, it's been an interesting 24 hours.

    I picked up the extra cable and connected the 8800GT. No issues booting OS X with both cards in it and fully powered -- other that I can't get the display drivers by netkas working yet (not initialized) for the Radeon -- and the EFI. Windows, however...

    Windows doesn't like two brands of cards in one computer so I had to remove the nvidia drivers. Still, with the card powered I suspect the EFI tries to hand over display output to the geforce and the ATI gets no signal to the screen. My current solution is to remove the PCI power cable from the geforce, which prevents it from operating, before booting into Windows. The HD5970 then works.

    [​IMG]

    (on flickr)

    The card performs amazingly well, that's no news, but in Battlefield: Bad Company 2 and only Bad Company 2 the system freezes / bluescreens. The on-motherboard diagnostic LEDs ERRA and ERRB are on when the system is frozen until a forced reboot. I've tried reinstalling the game, the drivers, removing the other card, etc. To no avail. I even ran linpack and furmark at the same time for a considerable amount of time to demand a lot of power from my system and see if I was simply stressing a rail or the PSU too much. Nope.

    I might do a memtest for an hour or eight but I doubt it's the FB-DIMMs. Perhaps installing 10.7 drivers could help but I'm rather afraid I've run into an issue with BC2 only, as the problem doesn't appear elsewhere.

    But yeah,the rest works great. If I want to boot into OS X I currently use the 8800GT. Are there guides for using ATY_Init and the latest netkas drivers on a 'genuine' Mac? I feel like I'm having some issues with the non-EFI compatibility of my card...
     
  22. macrumors member

    Joined:
    Jun 5, 2009
    #22
    Hmmm. Sounds different from the issue I was getting with the 4870 X2. When I ran Gears of War, everything was lovely and super smooth for about 15 minutes, and then the system just shut down, as if I'd held the power button for a force shutdown.

    I could restart straight away, but didn't run GOW again, just in case I was stressing something out and causing damage.

    I'm not sure if the MP 3.1 layout is the same as the 2.1 that I own, but isn't the first PCI slot the best for using a card like this? Maybe try running in windows with only the 5970 in slot 1, and leave the 8800GT out altogether? I know in my MP, the first slot is the fastest, but not being familiar with the 3.1 specs, this may not the the case for yours. Could be worth a try anyway though?
     
  23. thread starter macrumors member

    Cocoia

    Joined:
    Jul 19, 2010
    #23
    Basically, slot 1 (bottom) is a double-wide PCIe 16x slot, as is slot 2. I currently have it in slot 2 and the 8800GT in slot 1. This purely because the bottom of the HD5970 can get hot and I prefer to keep the hot part away from the memory cage, which 1 is next to.

    I've tried putting it in slot 1, with the 8800GT in slot 3, or without the 8800GT -- all possible combinations, really. No effect, the same problem in only one game persists. Hence I'm thinking it really is just the game. With the very intense stress tests I did it is impossible that BFBC2 is causing something to run warmer / drain more power or somesuch.

    Feh!
     
  24. macrumors member

    Joined:
    Nov 4, 2008
    #24
    Howdy, I just thought I'd chime in with my experiences of running a 5970 in my 2009 Mac Pro. At the moment I'm running the 5970 alongside the stock Nvidia GT120, and both cards work perfectly under Windows 7. I have my iMac 27" connected to the 5970 under target mode and the GT120 is powering my 24" ACD. Under OSX the GT120 works fine, and the 5970 remains inactive. I've run a few intensive games at 2560x1440 and haven't experienced any crashes or lock-ups so far.

    I haven't tried the netkas kext yet, so I don't know if the 5970 works under OSX. I'm just waiting for someone to confirm the method works in something other than a hackintosh!
     
  25. thread starter macrumors member

    Cocoia

    Joined:
    Jul 19, 2010
    #25
    After an hour or 20 of searching, I have found the interaction of the Mac Pro's Realtek on-board audio chipset and Bad Company 2 cause the freezes and BSODs. No issues with having two cards in there or with the HD5970. Phew!
     

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