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User profile for user: Marker227
Marker227 Author
User level: Level 1
4 points

Bootcamp 2nd monitor resolution changes upon restart

Here's my problem:


I have 3 monitors connected to my Mac Pro (specs listed below). Whenever I restart in Windows 7 (drivers updated, installed monitor control panel, Mac drivers updated) one of my monitors always gets screwed up with the resolution. I have 2 22" monitors and 1 28" monitor. The one that always gets messed up is the 22" screen with a resolution at 1680x1080. Windows 7 detects the resolution being about 600x800 or something. To fix this, I have to unplug the mini dvi port from the computer and simply plug it back in. The monitor instantly goes back to full resolution and then I have no issues until I restart again.


I don't seem to have issues if I leave 1 22" monitor and the other 28" monitor plugged in. This only happens when I have all 3 connected.


I've tried numerous times to update drivers and download the graphic card control panels, but none of it seems to help.


Would anyone have a clue as to why this happen?





Bootcamp - Windows 7 64 bit. (issue has happened even before I upgraded to 64 bit)



1 GB Radeon 5870



Model Name: Mac Pro

Model Identifier: MacPro3,1

Processor Name: Quad-Core Intel Xeon

Processor Speed: 2.8 GHz

Number of Processors: 2

Total Number of Cores: 8

L2 Cache (per Processor): 12 MB

Memory: 10 GB

Bus Speed: 1.6 GHz

Boot ROM Version: MP31.006C.B05

SMC Version (system): 1.25f4


OS 10.8.2

Mac Pro, OS X Mountain Lion

Posted on Jan 25, 2013 11:03 AM

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6 replies
User profile for user: gen_
gen_
User level: Level 2
368 points

Jan 25, 2013 4:14 PM in response to Marker227

The third socket doesnt have resolution detection on startup it appears. This would definitely be a driver issue, but it surprises me that nobody else has mentionned this in the the past. I would have a word on ATi/AMD forums, maybe the other poeple experiencing this issue have found a workaround.

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User profile for user: gen_
gen_
User level: Level 2
368 points

Jan 25, 2013 4:30 PM in response to Marker227

Strange. I naturally assumed that it would be the HDMI socket that has this issue.


Did a little digging and found this by Mr Grand Bennett. It was here: https://discussions.apple.com/thread/2746930?start=0&tstart=0


A related topic, but the same fundamental issues is being discussed nearby:


Can I use all three ports on the ATI Radeon HD 5770?


The movie version is that Mini DisplayPort does not convert directly to DVI, and the card cannot run three displays reliably unless you are using ACTIVE or POWERED adapters to convert to HDMI or DVI, which provide active conversion.


This is not your Mac Pro model, but you ARE using its display card, so these DO apply:


Mac Pro (Mid 2010), Mac Pro (Early 2009): Issues with three displays and multiple DVI, HDMI connections


Mac Pro (Early 2009), Mac Pro (Mid 2010): Supported display configurations

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User profile for user: Marker227
Marker227 Author
User level: Level 1
4 points

Jan 25, 2013 4:38 PM in response to gen_

I already have this setup the Resolution paragraph is speaking of.


I am using 2 Mini DisplayPort to Dual-Link DVI Adapter from Apple. One of the USB power sources is plugged into the computer and the other is in a USB outlet on a power strip. The third monitor goes straight into the DVI port on the card.



"If you use three displays, you should connect at least two of them with a Mini DisplayPort. You can also use the Apple Mini DisplayPort to Dual-Link DVI adapter or the Apple Mini DisplayPort to VGA adapter or just connect the devices to the graphics card using their native Mini DisplayPort connectors."

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User profile for user: Grant Bennet-Alder
Grant Bennet-Alder
User level: Level 10
127,633 points

Jan 26, 2013 4:51 PM in response to Marker227

I blundered onto this article and thought of you. I am not sure it applies, but maybe it will jar someone's memory:

Symptoms

In certain situations when you use Windows software under Boot Camp on a Mac Pro, the display may remain at 640x480 resolution (4-bit mode). Selecting other resolutions may have no effect.

Resolution

To use resolutions other than 640x480, you need at least two gigabytes (GB) of RAM installed in your Mac Pro.

from:

Mac Pro: Display set to 640x480 resolution with Windows

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Bootcamp 2nd monitor resolution changes upon restart

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