...and how to fix the problem
This article has been updated with corrections and new information, thanks to readers ZinZ and infeeee.
A few weeks ago, I got the CB3 ultrawide monitor from Acer. It is gloriously 32" wide and makes my video tutorials (of CAD software) easier to edit. The resolution is 3440 x 1440, which in shorthand is 5K 3.5K.
My newish Dell laptop runs with the new monitor, no problem: just connect any HDMI cable between the two. Here's a pic of the Dell running Camtasia video editing software on the ultrawide.
Last week I got the new X-based Mac Mini. I need it mostly only when I write about CAD software that runs on MacOS.
The computer had a problem right out of the box, when it didn't really understand it was connected to an ordinary 1920x1080 monitor. The image was too big, so that I could not access the menu bar. After a while, I was able to reach the menu bar blindly, and after a few reboots the Mac finally displayed correctly. Not a pleasant out-of-the-box experience
Next, I hooked it up to the Acer ultrawide monitor, but no joy. The monitor stayed blank, sometimes complaining "No cable attached." You might be able to imagine the time I wasted trying to get it to work. I have an ultrawide monitor and that Mac would work with it, darn it!
- I tried Apple tech support where two techies tackled my trouble. In the end, the final advice from Apple was, "Ask Acer tech support."
- I tried Acer tech support, and in the end the final advice from Acer was, "Ask Apple tech support."
I did some more mucking about, and on the second day finally got the ultrawide to work, but at the wrong resolution. Here are the resolutions listed by the Mac for the Acer monitor: none match the monitor's native resolution of 3440 x 1440 (click image for larger image).
Update 2: Reader infeeee suggested holding down the Option key while clicking Scaled. (Hold down the Alt key, when you have a Windows keyboard hooked up to a Mac.) It worked! The action forces MacOS to list all resolutions available, including the native resolution of 3440x1440:
And here is the the Mac Mini's output correctly displayed on the Acer ultrawide monitor:
As Management Speak (@managerspeak) so eloquently put it this morning, "The problem is that you are running the latest technology."
In my efforts to fix this problem, I came across important details at Apple's Mac Mini tech specs page, written confusingly. (Note that my Dell laptop supports three displays at once.)
- The HDMI port on the newest Mac Mini handles only 4K resolution. This is why the ultrawide monitor worked, but at lower resolution.
- The Thunderbolt port handles 8K. But I had no cable for this spec.
The Mac considers the HDMI port to be the primary display; one Thunderbolt port is used to provide the secondary display.
So, the new Mac with its X processor cannot handle what my year-old Dell laptop can: outputting more than 4K resolution out of its HDMI port the correct resolution for the monitor automatically. This makes me appreciate my Windows- and AMD-based Dell laptop even more. A reader suggested that a higher quality cable might help, which I have ordered.
Then I found that 8K cables are rare. I finally found an 8K cable that handles Thunderport at one end with DisplayPort at the other. (The monitor has two HDMI and one DisplayPort ports.) I ordered it and await its arrival.