1080 in a Mac Pro, what to expect.

Discussion in 'Mac Pro' started by Draeconis, Dec 4, 2016.

  1. Draeconis, Dec 4, 2016
    Last edited: Dec 4, 2016

    Draeconis macrumors 6502a

    May 6, 2008
    Hi all, posted this in another thread, but I thought I'd repost it here in case people didn't see it.

    So, I recently migrated fully over to Windows 10 a) to see if was possible and b) to have more freedom with GPU upgrades. I recently bought a 1080 and installed it. Not tested it under macOS for obvious reasons, but under Windows 10 it runs fine :) A couple of notes people might find interesting or helpful;

    • You'll need a female 2x6-pin to male 1x8-pin to convert the stock PCIe power cables to power the card. I'm sure you can achieve this other ways, but this is how I did it and it works perfectly.
    • No boot screen or Windows loading screen are presented; only the login screen. Presumably this is because of Mac EFI compatibility or lack thereof. It does actually boot faster than when the 680 was installed though.
    • Updating drivers makes the screen go black for longer than I'm used to. Don't panic if this happens to you, give it a minute or two and it'll come back.
    • It looks sweet when the logo is lit up. Wasn't really expecting that.
    • Even though it's bottle-necked by a W3670, 1066Mhz RAM and PCIe v1.1*, it absolutely flies. The Division at 1440p gets over 60fps reliably, and DOOM at 1440p on Ultra gets 120fps at times. Very impressed. Yes it's probably not as good as being in a brand new i7 6700k rig, but I can't afford that at the moment.
    • Running a 27" 2010 Apple Cinema Display via a female mini-displayport to displayport adapter than I received with the 680. Works perfectly.
    • Only issues are after installing the 1080; Sleep appears not to be an option any more in Windows 10. Unsure why, perhaps this is another EFI thing.
    • The 'Advanced Startup Mode' also doesn't quite work. You can choose to restart in different diagnostic modes, but when the machine restarts, the screen that allows you to select one doesn't appear. Again I assume this is because the Mac EFI can't initialise the GPU.
    • Other low-level windows like CHKDSK don't appear either.
    • Weirdly I can see a second display connected, but I'm only using one DisplayPort connector. Unsure why this is.
    • Firestrike score is around 14,000; ~2,000 less than on i7 6700k rigs. Still better than the 6600 I was getting with the 680.
    • More a general Windows point but one worth making; if you're having issues with System Restore, you'll need to find and move AppleHFS.sys and AppleMNT.sys in Windows/System32/drivers/. Move these elsewhere and reboot, and System Restore should work properly. Obviously you wouldn't want to do this normally, but since you have a GPU that macOS doesn't support, it shouldn't affect you any more.
    *(This is because it's a PC card. The 1080 can do PCIe 3.0 and the X58 chipset can do 2.0, but because it can't talk to the Mac EFI, it never boosts the PCIe link past 1.1).

    If you guys have any questions, please give me a shout in this thread.
  2. Draeconis thread starter macrumors 6502a

    May 6, 2008
    Hi all,

    Just wanted to do a brief post after the build 1703 update.
    • Sleep now works again! (But a bluetooth device like the Apple Wireless Keyboard can't wake it).
    • My FireWire soundcard stopped working, I'll have to re-install the 680 and reboot into option 7 (Device driver signing disabled) to reinstall the drivers.
    • 2nd 'screen' issue still present.
    If I find anything else, I'll let you all know :)

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