Crash on wake with second monitor plugged in- Gigabyte HD 6870 1GB

[gdubduc]

Hi folks.

I've been toying with my upgraded rig for the last few weeks and finally, though the process of elimination, figured out why I'm getting a crash-on-wake situation after I've been using the machine for a while, but not while doing the install and such. As a process, everything goes smoothly through install, transfer of applications from backup, etc. Along the way, however, things start going south, with crashes that happen whenever I try to wake the machine back up from sleep that send the system into a restart loop where it tries, and fails, five times to restart the system before finally getting to the bootloader.

After four reinstalls and about 25 hours worth of troubleshooting, I have nailed it down to the addition of a second monitor. When I plug my second Dell U2711 into the 6870 via a DP-MiniDP cable, the monitor works swimmingly. However, whenever I try and put the system to sleep or reboot, I end up in that same weird bios loop. I have tried both MiniDP ports on the card. I am currently running my primary monitor off of DVI-1. I can currently plug the monitor in while the system is awake, use it successfully and then unplug it without issues. However, if I leave it plugged in, the system will not autosleep and when I put it to sleep manually, I get the bios loop.

I am using GraphicsEnabler=Yes and have the card recognized in About This Mac, Duckweed automatically selected and full graphics acceleration. Attempts to use PCIRootUID=1 with AtiConfig=Duckweek and AtiPorts=5 yield the default Radeon Framebuffer instead of Duckweed. I haven't yet tried the HDMI cable, but that's my next step.

Any ideas on how to get this rig going with both monitors with sleep/wake and reboots? Any help is greatly appreciated.

 

[gdubduc]

Does anybody have an idea on this one? I've done yet another reinstall to work out other issues now and have everything running flawlessly with the exeption of the dual monitor issue. Again, I can boot with the second monitor plugged into DP1 or DP2 just fine, I can use the monitor without any problem, but when the machine is put to sleep (either manually or autosleep), it will not wake up. Even pressing the power button does nothing. I have to switch off the PSU, wait a minute, then start it up again.

Both displays worked fine on the same card with Mountain Lion on my old motherboard, so this is a new issue related to this install and the GA-z77x-ud5 motherboard.

Any assistance is greatly appreciated.

 

[gdubduc]

OK, more testing. I'm only pulling 225 watts at the most through the PSU with the CPU at 100%. I have a 750 watt PSU. So the problem isn't there.

Switching the port on the PSU where the cables from the graphics card plug in (it's modular) did nothing.

Sometimes the crash on wake causes a CMOS reset, sometimes it doesn't. However, in both cases, I have to power off the PSU and unplug the second display cable to the graphics card before it will boot.

Anybody? Bueller?


Thanks,