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Mac Pro (Late 2013) Dual monitors freeze on startup?

I've got 2 monitors, 1 HDMI and 1 MiniDisplayPort/DVI into Thunderbolt, and the computer can't start, it crashes during the boot process. The main screen freezes just as the login comes up, the MDP screen is scrambled, and the mouse cursor is a spinning pizza.


The only solution so far is to remove the MDP cable during startup, but that is a dealbreaker because dual monitors is the sole reason I bought this, and c'mon it's a really expensive computer -- even my old MacBook could handle 2 monitors!


Any insights or solutions appreciated.

Mac Pro, OS X Mavericks (10.9.4), Late 2013

Posted on Jul 28, 2014 12:18 PM

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70 replies

Jul 28, 2014 1:40 PM in response to lllaass

Thanks Illaass,


Yep, I read that in the manual before I hooked it up, so I've been using a different TB bus. Wish it were that simple.


I haven't tried another monitor or adapter, but it's the Apple-made single-link DVI MDP adapter form my MacBook and I used it for years. It also works fine after the new Mac Pro starts up. I could try a dual-link DVI adapter (~$100) but I'm not running above 1920x1200 so I shouldn't need to.


I'm wondering if anyone who uses this display configuration (HDMI + MDP DVI on a Late 2013 Mac Pro) can boot without crashing?


I'll try resetting the SMC and zap the PRAM while i'm at it.

Jul 30, 2014 9:52 AM in response to vett93

Hey Vett,


Not yet, but those guys at the Apple store are really great. How awesome to be able to physically bring this in and talk to a knowledgeable guy down the street (for free), instead of something useless like a call-center where they just read from the manual.


Anyway they ran some quick tests but couldn't find anything conclusive without taking it in for a few days for extensive diagnostics. In the meantime I'm trying to isolate the problem. It happens even with no other peripherals connected, so it's not the USB HD. The Genius guy said it could be a software conflict, but the only non-OSX software I have on here is Sophos and Adobe CC, both of which I need.


Next I'm going to try replicating the problem in Safe mode (hold down SHIFT when you hear the startup chime). I suggest you try that too, let me know if it helps. After that I'll try uninstalling those programs and see if that does anything.

Aug 26, 2014 3:35 PM in response to x.graves

Hey x.graves,


My company bought 2 mac pro's, each with the same dual monitor setup, which we are using to edit in avid. One monitor is connected HDMI to HDMI, bus 0. The other monitor is connected HDMI to thunderbolt, bus 1. I am having the exact same issue you are having with BOTH of the computers. Freezes on startup when the login screen comes up, and second monitor is jumbled. Have to unplug second monitor just to start it up, and plug it back in after login is complete.


When i used a different cable setup, i was having a separate issue within avid where the secondary screen was showing correct color while paused, but then de-satuarated the image whenever i pushed play. But even that setup was causing the startup issue as well. The setup I am currently using fixed the avid issues, but kept the startup issue. So i haven't been able to successfully startup a mac pro with dual monitors yet, which i agree is extremely annoying given the cost of these machines.


Just wondering if there's any update to fixing this. Thanks.


OSX 10.9.3 Mavericks

Mac Pro (Late 2013)

Aug 26, 2014 4:34 PM in response to NoRoadsProd

Vett: After doing safe mode and a few other zaps, mine was fine for about a week too, then the problem came back.


NoRoadsProd: I'm starting to be convinced it's a hardware issue. Do you have Sophos and/or Adobe CC on your machines?


I bought a new miniDisplayPort adapter and new hi-speed cat2 v1.4 HDMI cables, and neither of those had any effect on the problem.

Aug 27, 2014 1:35 AM in response to NoRoadsProd

Hi x.graves

I can recreate the exact same issue as the OP when I have my Caldigit T3 Thunderbolt Raid plugged in and switched on. When the T3 is switched off the Mac Pro starts up with no issues. However, after reading this whole thread I'm wondering if its not one of my monitors as I have the wake from sleep issue reported in another thread where one monitor does not come on after sleep.


I deducted it was the T3 after removing all other USB and thunderbolt devices and plugging one in at a time. I've contacted Caldigit to see what they say.


Ta


Drew

Aug 31, 2014 3:06 PM in response to x.graves

I have the same problem. Sometimes (very randomly) when I start up my Mac Pro with 4 monitors, it goes to scrambled bars and spinning wheel of death. If I start it up with only one monitor and hold down Cmd+opt+p+r it will reset the problem, but eventually it will happen again. 3 of the monitors are Optiquest-Q19wb and the fourth monitor is a Sony 55 inch flat screen. The flat screen causes the most problems when starting up or turning it on when the computer is already running.

Sep 1, 2014 9:02 PM in response to x.graves

I've seen this on occasion, maybe one out of five times I do a reboot. Solution in almost every case has been to unplug all the USB devices and reboot. In one instance, had to unplug all thunderbolt devices as well, except for the monitor. I really don't think this is any specific device incompatibility, since I've tried a few combinations. The machine is very stable otherwise.

Sep 2, 2014 10:42 AM in response to EdAnuff

Actually, spoke too soon, had the problem come back in spades this morning. Unplugged everything but the two monitors and it still wouldn't complete boot. Unplug the second monitor, power cycle, and it then works. Plug everything back in and restart, and it freezes at login again. Trial and error shows that with just a single monitor and anything else connected to Thunderbolt and/or USB and no problem, add the second monitor and it doesn't start. These are just two 1920x1080@60Hz HP 2310m monitors with mini-displayport to DVI adapters, so nothing esoteric. One monitor is on thunderbolt port 1 (bus 1) and the other is on thunderbolt port 2 (bus 2), but I've tried all the combinations and it doesn't seem to make a difference.

Sep 2, 2014 11:16 AM in response to EdAnuff

NoRoads - totally, it's supposed to be able to handle a lot more than 2 monitors. I'm using:

- primary: Samsung 46" LED TV via HDMI > HDMI (bus 0)

- secondary: Samsung 24" LCD monitor via DVI > MDP / TBOLT (bus 1 or 2)


Chesire - I did something that fixed mine for about a week, it might have been CMD + OPT + P + R


Ed- Yep, that's the same issue we're having. The USB ports don't make a difference, it'll crash with nothing plugged in. So you're not using the HDMI port at all? Just dual TBolt monitors?

Mac Pro (Late 2013) Dual monitors freeze on startup?

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