Q: Flashed gtx980 web driver causing boot issues
MacPro 5,1 2009.
2 x 3.33 Ghz (12 core)
32 GB
Nvidia GeForce gtx980 4gb (Flashed with EFI).
I've just bought this mac and I've been having an odd issue with it, I can't find any similar problem discussed online.
Summary of the problem.
Mac came with Yosemite 10.10.5, I updated it to 10.11.1 (after a hassle with getting suitable web-drivers). After installing 10.10.1 I install a bootcamp partition with win7 home premium 64bit.
I notice a boot issue where the mac does not auto boot (regardless of what startup disk is selected in MacOS), after powering on the screen stays black and nothing happens.
Holding alt on startup will bring up the boot menu and I can select MacOS 10.11.1 and it boots then with no problems. However selecting windows will freeze the mac completely on the boot screen, it doesn't get close to booting windows, just a 100% freeze the moment windows is selected.
Diagnosing.
PRAM and SMC resets didn't work (I can't remember what else I tried, it's been a stressful few days). So I installed an older apple certified AMD radeon card and both problems instantly go away, mac now auto boots and windows doesnt freeze the system.
So it's something to do with the gtx980 and web drivers. So I perform a clean install of yosemite again, as that was the OS on the mac when purchased. However after updating the correct webdrivers under 10.10.5, the problem re-occurs, no auto-boot and windows freezes on the boot menu.
I'm currently running the 980 on 10.10.5 and there don't seem to be any other issues with it. The mac supplier is shipping me a replacement card tomorrow, but I was still hoping that there could be a software fix somewhere out there or something else I could try. Although most people I speak to are pretty stumped and haven't seen this issue before.
Posted on Nov 9, 2015 7:20 AM