Force the resolution on a headless mac mini server

Question

I have a Mac Mini server running Mavericks. It has no monitor connected. I use Remote Desktop on my laptop (also running Mavericks) for I/O to my server.

When I use Remote Desktop and go Full Screen I get a 1280x1024 screen sitting in my 1680x1050 screen. Is there any way to force the client (Mac Mini) to use a setting of 1680x1050 so I get a real full screen?

I tried holding down the option key while clicking on Scaled in Display -> System preferences. All I see is a new button in the bottom right that says detect displays. Clicking on it does nothing. The only resolution shown is 1280x1024.

My Mac Mini Server is a late 2009 with an Nvidia GeForce 9400 graphics card.

Answer 1

I'd like to offer an improved answer, that the author may consider for the question. The previous answer's AirDisplay drivers actually messed up my remote client, and left me with 16 virtual displays, all with the same information, where I couldn't click anything. Luckily I know how to navigate Activity Monitor with the Keyboard :-) .

I found the following to work perfectly, assuming that you are using Apple Remote Desktop:

• Download Display Menu (Free on Mac App Store)
• Install the app, and for my use cases, 1680x1050 was the proper resolution.
• Your screen will go black and you will be 'locked out', despite the resolution properly switching.

• Your screen will black out. Many recommend something similar to the following Terminal commands. I DO NOT recommend the following:

  sudo ps auxwww | grep loginwindow | grep -v grep | awk '{print $2}' | xargs sudo kill -9

• The reason the last line does not work is because it actually terminates your login session. That forces the screen resolution to revert (in my case, back to 1280x1020), and you'll be back where you started.

• Instead, use the following command over Apple Remote Desktop or via SSH:

  killall ScreensharingAgent

• NOTE - if using Apple Remote Desktop's Send Unix Command, instead of using sudo, click the radio button to 'Run as User', and just enter root.

This command terminates the Screen Sharing session, which at its core is what Apple Remote Desktop uses. It retains the logged in session, which retains the screen resolution you set with Display Menu in earlier steps.

• 2nd Note - if your dock is screwed up, simply send killall dock

I have yet to log out of my current session on my client machine, so this may only be a temporary fix. However, its the only way I have found that satisfies my OCD with proper screen real estate consumption.

Some things that helped me find this answer:

1. Alternative to this answer on SuperUser, doesn't accomplish what I wanted, but good to have for reference material
2. MacWorld Hints, which held the elusive answer!

Some alternatives that others have presented below, in case this answer does not work for your system:

1. QuickRes App
2. SwitchRexX
3. Resolutionator

Answer 2

Simplest solution (for macOS versions prior to Catalina):

Just hold the 'Option' key while you press on 'Scaled' button in the display settings in system preferences. This will bring up all available resolutions and you can change to whichever you like.

Note that this doesn't work in macOS Catalina and above.

Answer 3

Just downloading Display menu from App Store (free) and choosing highest resolution worked for me on Yosemite. Now running headless with great remote screen resolution. No other actions required.

Answer 4

SwitchResX worked for me.

It is a shareware utility that installs itself into System Preferences. From within the panel, it allows you to force the default resolution of an external monitor.

Answer 5

Many people seem to have good luck using the AirDisplay drivers to achieve this. There's also headless dummy adapters you can buy, although that might be overkill. If you're keen to building your own there's a way to do that as well.

More information here.

Answer 6

Use cscreen from Brew. It's free and surprisingly easy.

brew install Caskroom/cask/cscreen
cscreen -d 32 -x 1920 -y 1080 -r 60

Answer 7

Here's an alternative, based on CDD's answer that will work for Lion. The Display Menu application doesn't work on Lion.

1. Go to System Preferences, Displays, and choose the resolution you want. Switch to this resolution. The VNC display will freeze. Press Return a couple of times to accept the resolution anyway. You'll see the menu bar getting wider for a moment, but not the VNC windows. Then it'll auto-revert to how it was.

   This step is necessary to allow this resolution to show up in the menu chooser in later steps.

2. Enable "Show displays in menu bar".

3. The display chooser may still not show up in the menu bar for lack of space. To make space, go to Preferences, Users & Groups, Login Options and disable "Show fast user switching menu". Disable anything you don't need in the menu bar until there's enough space for the display chooser to show up.

4. Close Preferences. Log in to the same computer using ssh separately. Choose the desired resolution from the menu bar display chooser, press return a couple of times, and now you can run killall ScreensharingAgent from the ssh session. The VNC window will now resize to the correct resolution.

This convoluted method has worked for me.

Answer 8

Beeing in lockdown and using a remote headless mac mini, I found a free working utility from Mac App Store: EasyRes

Link: https://apps.apple.com/app/easyres/id688211836

Answer 9

For its simplicity, I prefer the QuickRes application.

Answer 10

This Finally solved a similar annoying work-related monitor problem of mine. Might help you too. My development-work computer is an iMac sitting on my Baby Grand Piano. But for ergonomic reasons I prefer to work remotely from my old MacBook Pro 17” over home wifi to the iMac using Apple’s screen sharing app. Works fine but theres a niggle. My MacBook screen res. is 1920 x 1200 but the iMac is 1920 x 1080 maximum native. So for remote work my screen real estate is squashed. I get to use only 1080 lines out of the 1200 available on my MacBook Pro, with black letter boxing above and below the video. A waste. To my rescue comes a tiny product: fit-Headless by CompuLab for £21 - sold on Amazon. You plug it into the second monitor video port where it acts as a dummy second display with variable screen resolution options up to 4K. However on receiving it - I plugged it into my VDI port. It appeared in preferences as a second screen. BUT..... woe woe woe .. with all the options of screen res - going all the way up to 4K..... NO BLOODY 1920 x 1200 !!!! W T F !!! Googled around. And came across and downloaded demo of an app called SwitchResX which does all manner of things to do with monitors. It too had tons of resolution options BUT STILL NO 1920 x 1200 !!. BUT..... hidden away was a tab where you can set up your own custom screen res. So added one for 1920x1200. And HEY PRESTO ! for an extra £18 for SwitchResX I can now work remotely on my iMac from my Macbook at the same high resolution as my macbook. No letterboxing. More pixels to poke, drag and mouse around with.. HAPPY DAYS ! [ PS: these fit-Headless adapters are actually intended for people using Mac Mini’s as “headless” servers etc where they administer them remotely and don’t want to have an actual monitor attached. For example because it sits in a rack or on a shelf... ]

Answer 11

Resolutionator worked for me on El Capitan.

Answer 12

Display menu from App Store (free) worked for me too, running OS X 10.10, Yosemite.

I wonder is there a way to force it through command line / conf files. For now Display menu is the way to go for a Mac headless computer.

Answer 13

At first, just Option+clicking in System Preferences > Displays between "Default for Display" and "Scaled" only brought up 1280x1024 and 1280x720 for me.

However, after I changed the Apple Screen Sharing app's preference under Display from "Scale to fit available space" to "Show in full size", then 1920x1080 and a whole range of other options came up.

This was valuable to me because I was looking to avoid any apps requiring SIP to be disabled and any apps only available through the App Store. I don't have enough rep to comment on one of the more upvoted posts referencing a screen shot of using the above method on a Macbook but hope this helps someone!