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

Correct, just on the 2 thunderbolt ports, no HDMI. The System Information app shows that both monitors are on the AMD FirePro D500 on "Slot-2".

Makes me wonder whether it's really port-related at all or an issue with the graphics card driver.

I set up a new macpro at work yesterday. My dual monitors are (2) Asus VS247H-P, they are going into the TB ports 4 and 6, and AMD FirePro D500 video card slot-2.

I am having the freezing issue when coming back from sleep, during restart, or putting from power off. The second monitor is scrambled and I have the beach ball of death on monitor 1 over the login screen.

System Specs

Model Name: Mac Pro

Model Identifier: MacPro6,1

Processor Name: 6-Core Intel Xeon E5

Processor Speed: 3.5 GHz

Number of Processors: 1

Total Number of Cores: 6

L2 Cache (per Core): 256 KB

L3 Cache: 12 MB

Memory: 16 GB

Boot ROM Version: MP61.0116.B05

SMC Version (system): 2.20f18

Illumination Version: 1.4a6

I have the same issue using a LG ultra wide 34um95 monitor and a older DVI monitor. The DVI almost always displays while the thunderbolt LG monitor is finicky and wants to go into sleep mode. The LG monitor will not show the boot screen so if I want to boot in boot camp, I can't see the hard drives for selection.

I dont know if it's the monitor or the Mac Pro. I also tried the HDMI on the LG and it does the same thing. I think it's Apples issue and not LG's,

I'll call LG to see what they say.

Try it with just that LG monitor and disconnect the other. If it works, then the problem is Apple. My nMP works well with just one monitor. But when I use both monitors, it has freeze and wake up problems.

Apple Engineering team has been working on my issues for 2 1/2 months. Still has no solution.

I'm chiming in because this issue has been with me from day 1 of the nMP which was delivered 9/8/14! I have 2 connections, HDMI to the HDMI port and HDMI to MiniDP going into a separate TB bus and when both monitors are powered on the nMP freezes on start up with a grey screen on the main display and the second display is black with garbled images. I've seen pictures of this scenario on other posts here on the forum. The way I can get the nMP to boot is simply power off the second display before I boot up, then power it on a few seconds after the login screen appear and all is good. This saves me from physically unplugging the display from the nMP!!!

What a drag though, for the price of these machines this should not be happening. I can only hope Apple Engineering read these posts and deal with it ASAP!

Apple support suggested I have the unit checked out for hardware errors at an Apple Store so I will go ahead and do that on 9/13. We'll see what happens. I bet the unit doesn't show any hardware malfunction?

nMP 3.5ghz 6 Core

D300

I called LG this morning, the tech immediately told me the problem I'm experiencing is an Apple Mavericks / Mac Pro issue and is known at LG. There is no fix on LG's side. They had me try the same two monitors on my 2012 Mac Mini which is also Mavericks and both monitors work fine, no issues. So the Mac Pro is the problem. There is something wrong with the Thunderbolt Ports / HDMI port on the Mac Pro interface with the software.

I can not use my 34" LG widescreen Monitor with the Mac Pro because it does not turn on anymore, the monitor works fine though on my Mac Mini using thunderbolt.

I'm taking in my Mac Pro to the genius bar tonight and have them deal with the problem. They can waste hours trying to figure this thing out.

Oh by the way, I have boot camp installed with Windows 8.1 64bit and I believe boot camp is also adding to the lock-up no screen issue.

If I use an old DVI or VGA monitor with a mini display port adaptor, the Mac Pro works fine with one monitor - does not make sense. Only the new monitors with the energy star auto-sleep have issues.

TTo make things more confusing, I have an Elgato external Thunderbolt SSD which contains my Final Cut Pro partition, with the internal ssd handling my FInal Cut X partition. The lockup only occurs with my Final Cut Pro partition. I am suspecting that perhaps something became corrupted in my OS (on the Elgato) that is causing the freezing.

Tinpig - Thanks for the suggestion of just simply turning the second monitor off on startup, and back on after. That's much easier/less annoying than unplugging/plugging back in. That worked for me.

i don't have boot camp installed on either of these computers so i don't think that's the issue. I think its just a video card issue that they need to release a new driver for. But they say you can use up to 6 monitors with this computer, so has anyone tried plugging in more than two monitors?

I saw on another thread that a person had 3 displays on the 2013 Mac Pro and one display would not wake up. They said it was annoying because the one the would not wake up was the actual desktop and the other two screens would then reformat their screen sizes to include the desktop. When the 3rd screen would finally work, each and every time the screen formats had to be changed. I think the title of the thread was "annoying......"

NoRoadsProd - I'm glad that worked. So to clarify, this problem occurred with an out of the box nMP. No other peripherals were attached or software installed (the machine was factory fresh).

I'm extremely annoyed this is an issue! Ah the joys of new machines?!

yes, this problem occurred with not one, but TWO, out of the box nMP. no other peripherals or software. Its all very annoying.