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

Tomorrow I'm going to try both monitors using the VGA outputs with VGA to mini display port adapters and plug each one into a separate TB port/bus.

I have the computer. They gave me a tool to collect logs. I have done that twice already. They want me to continue debug for them. But I don't think so. I want my money back.

I spoke too soon. This morning i had the freezing issue when i turned the second monitor off before startup. yesterday it worked, today it didn't. unplugging/plugging back in still works every time.

Just booted mine and it worked with the second display being off before powering on the computer?

Morning x.graves, thought I'd throw in a little update. Managed to get the system to boot with both displays powered up 6 times so far this morning, everything from system restarts to system power off.

This is the setup:

Display 1, HDMI to MiniDP (cable) bus 0 port 6.

Display 2, VGA to MiniDP adapter (Apple Brand) bus 1 port 3.

I will let you know if this combo fails to boot at any time, fingers crossed, although I don't really want to be saying that when I've spent rather a hefty amount of $$ on this system!

As I'm not doing video or graphics (audio only for me) the VGA will work as of now but I'd still like to see this resolved.

Correct, no HDMI to HDMI connections on the system but as stated I am connecting Display 1 using HDMI to MiniDP cable

http://www.amazon.com/Cable-Matters-DisplayPort-Thunderbolt-Compatible/dp/B004CA DY9I/ref=sr_1_1/178-0624326-8828248?ie=UTF8&qid=1410540514&sr=8-1&keywords=thund erbolt+cable+to+hdmi

Thanks Tinpig.

I did some other configurations and it seems to be completely random of what works when.

This one has worked multiple times in a row, and then decided not to work anymore:

Primary monitor: HDMI to DVI cable (belkin), DVI to miniDP (apple brand) into port 2 (Bus 2)

Secondary monitor: HDMI to miniDP (same cable matters cable as tinpig) into port 1 (Bus 1)

the above worked when i had no thunderbolt devices plugged in (even if the thunderbolt cables were connected to nothing on the other end, it still didn't work). i had to remove the cables from the mac pro for it to work.

i got the freezing issue on startup if i plugged any monitor into Bus 0

i got the freezing issue on startup if i plugged both monitors on the same bus.

That's all i got for now.

Sorry, scratch that second to last line. It didn't work on bus 0 cause i had a thunderbolt cable plugged in. I got it to work plugging primary monitor to bus 0. but didn't work plugging into same bus as secondary.

I read that someone used an active mini display port to DVI adaptor to reduce the Mac Pro screen problems and I think this is our best clue / option to look into. This is what I'm thinking: AMD, the manufacture of the D300, D500, D700 video cards are a version of the AMD FirePro. These cards use a technology called AMD Eyefinity Technology. When I did a search on Amazon for active mini display to DVI just now, guess what - some cables are AMD Eyefinity Certified. Not all are, just some - for example: Cable Matters Gold Plated Active Mini DisplayPort to DVI Male to Female Adapter is Eyefinity Compatible. These cables adaptors are expensive $25-30. They have chips in them to create extra power for longer run wires and to make them compatible with AMD Eyefinity.

So maybe this is the direction we need to go and try some of these AMD approved Eyefinity adaptors. The AMD D500 is similar to the Firepro W8000 which has Eyefinity technology.

I too have a 2013 Mac Pro 6 Core, D500 that is 1 month old. I have dual monitors, a new LG 34" ultra wide thunderbolt monitor that will not work - it's stays in sleep mode most of the time and a Dell DVI 22" monitor. My Mac crashes constantly on startup and I can't get the LG display to wake 75% of the time. I took my Mac Pro to the Apple Store where they hooked it up to a couple Apple Thunderbolt monitors with no problems - reboots like a champ - of course. I take it home, same issues with my monitors. They (Apple) blame LG for driver issues. I called LG support, they said this is a know issue with Apple's Mac Pro - display problems. AMD states Apple writes the driver software of their D300, D500, and D700. No one is doing anything to fix our problems.

I'm ordering a couple of these ACTIVE adaptors and I hope it works!!!!!

Thanks for the info. I'll look forward your findings.

Just to make sure we don't lose this fact - the current workaround is to enable auto-login, which isn't great security-wise, but at least you'll always complete boot. That strongly implies a software problem rather than hardware. However, It would be great to find out what combination of interfaces are being used and whether there's always a miniDP-to-DVI interface in the mix. Is anyone having this problem with either Apple TB displays or Cinema Displays? What about miniDP-to-DP with 4K displays?

On the other hand, reading this Apple Mini DisplayPort adapters: Frequently asked questions (FAQ) does indicate that the Apple miniDP-to-DVI adapter is a passive adapter and I'd assume most inexpensive 3rd party cables are as well. Looks like Monoprice also makes a $15 active adapter. Important to note that these are all single-link, so if you're going to more than 1920x1200, you'll need a more expensive dual-link adapter, but those are always active adapters anyway, so theoretically if this is really a problem with passive adapters, you wouldn't be seeing it with those higher-resolution monitors to begin with.

I double checked and AMD Eyefinity is only operational on 2013 Mac Pro's Running Windows 7 & 8 on Apple's boot camp, it does not run in Mac OS. This may be why my LG monitor will not work on Windows 8, but will mostly boot up on Mac OS. I also learned that Apples Thunderbolt cable is "active" and not passive like regular cables - these should work but they don't with my LG thunderbolt monitor.😠

I ordered a mini DP to DP cable on Amazon - just arrived today and I can now boot between Windows 8 and Mac OS (about 15 times with no major issues).

I do get screen flicker (unbearable) on my LG 34 ultrawide on the Mac OS with the DP adaptor (passive) and I figured out that if I plug in a HDMI monitor (even turned of) into my Mac Pro the flickering completely stops. And I mean completely stops - the monitor is perfect. When I unplug the HDMI the flickering comes back.

I have this wire adaptor on the way: "Accell B112B-001B 10-Inch UltraAV Mini DisplayPort/DisplayPort Female Adapter - Black" which is AMD Eyefinity certified and will report in it when I get it tomorrow. If cables solves my problems I will be ****** at both LG and Apple for wasting my time and not knowing this beforehand.

Bottom Line: Cables are considered hardware and I think we forget that they play an important role in the function of our computers. By the way, AMD states that you have to use an "active" adaptor to run more than 2 monitors on each AMD FirePro W8000 card, which is similar to the D500. Hint - theoretically Apples Thunderbolt cable are "active." Regular mini DP to HDMI/VGA/DVI are "passive."

Tentatively appears today's 10.9.5 release has fixed the problem but will need to give it some time before knowing for sure. The release notes for 19.9.5 make no mention of this fix being present in this release.