Maximizing Mac Mini Screen Sharing Resolution - RESOLVED

[Tim0]

I'm currently on the road with my mac mini 2012. A friend I'm staying with has an iMac 2008 which I'm using as a terminal for my mini via screen sharing mode. However, running a mini headless ends up in poor graphics. They also have an old 15-inch DVI monitor that I can hook up to the mini to get the graphics chip going, but I'm still limited by the monitor's 1024 x 768 resolution. Is there any way to remedy that and have mac mini running full screen (1680x1050)?

 

[NazgulRR]

Yeah. Get an EDID HDMI/DVI (depending on the connector you need) dummy plug. I got a cheap one off eBay that goes up to 1900x1200 for my 2009 Mac Mini.

 

[Tim0]

Thanks, it will probably work as a long-term solution - however, I need to come up with something right away, and eBay orders take time. I was thinking more along the lines of Display Overrides, i.e. http://fullreels.com/en/video/5371600/Custom-Resolutions-in-Mac-OSX-no-software-necessary
but for some reason it doesn't quite work for me - I can't seem to get proper display data via

ioreg -lw0 | grep IODisplayPrefsKey

command.

I have an old ViewSonic VG510s serving as a dummy, but the command results in something else that does not have an override entry:

"IODisplayPrefsKey" = "IOService:/AppleACPIPlatformExpert/PCI0@0/AppleACPIPCI/IGPU@2/AppleIntelFramebuffer@2/display0/AppleDisplay-5a63-ca18"

The only entry I have under DisplayVendorID-5a63 is DisplayProductID-ae03, and the command shows ca18.

 

[Tim0]

RESOLVED!!! Yay!


Here's what I did, perhaps someone else will find it useful.


1. In Terminal, type:


ioreg -lw0 | grep IODisplayPrefsKey


2. You will get a string ending with "... AppleDisplay-xxxx-yyyy" (numbers at the end will vary).


3. In Finder, go to


/System/Library/Displays/Overrides/


Find DisplayVendorIDxxxx folder

See if this folder has a DisplayProductIDyyyy file


If the file is there, you might want to copy it to another location for future use.


If there is no file with that name (like it was in my case):


4. Copy another file (I just used the largest file from DisplayVendorID610 (Apple), namely DisplayProductID-9cd7, you may want to try something else), paste it into DisplayVendorIDxxx folder and rename to DisplayProductIDyyyy
UPDATE: Another (and likely more proper) solution would be to use the display profile from the "terminal" Mac (in my case, iMac 2008) by running ioreg -lw0 | grep IODisplayPrefsKey command there.


5. Reboot.


After reboot, I have an iMac display in Display properties, and access to all resolutions up to 1920x1200. I suppose you can dig deeper if you like and find something larger too, but this works good enough for me.


Disclaimer: The display I use as a dummy is an old, broken, 15-inch ViewSonic with no AC adapter (yes, not plugged in, attached to Mac Mini via DVI cable). I have no clue what this solution does to a live monitor, so use at your own risk.

 

[NazgulRR]

So is that a completely software solution? I believe the use of a dummy plug enables the gpu which improves the performance, no?

 

[Tim0]

No, I'm using an old ViewSonic display as a dummy plug. It is broken and not plugged in, but Mac Mini can still recognize it and improves GPU performance. However, without the software solution it only runs at 1024x768 (native resolution for that display).