Custom Resolutions & A Rotated Display

Dec 2, 2018
MSI x99a Gaming Pro Carbon
Intel Core i7 6800k
Nvidia Titan X (Pascal)
Hi all,

First Hackintosh build here in about 10 years, but after about two days of toiling around with the installer, Clover, and the Nvidia web drivers, I finally managed to get a fully functional High Sierra 13.6 installation running on my computer.

I suppose everything is working as intended in MacOS, but one minor (but deal breaking, for me) problem I noticed has me stumped. Probably because it seems like I'm a 0.1% edge-case and I can't find anyone discussing this issue in the same context, and similar solutions in different contexts don't seem to work.

Specifically, I have two 27" 4K LG monitors. The main one is in landscape, and the other in portrait. Rotating the side monitor after the Nvidia drivers were running was simple, just a quick stop in System Preferences, Display settings, then changing the rotation of Monitor (2) to 270 degrees. Done, right?

Well, by default, MacOS sets my scaling factor to the largest setting, which is 1080p scaled up to 2160p. Hence everything was far too big for my liking. I found the setting to change the scale and on my main monitor, it shows the "looks like" options: 1920x1080, 2560x1440, 3008x1692, all the way to 3840x2160. So I selected the "looks like 1440p" option and everything was much improved.

But then I went to change the scale on my second (portrait) monitor... and the options for scaling are completely different! The options here are: 648x1152, 846x1504, 1080x1920, and 2160x3840. In other words, I can go absurdly big, absurdly small, and nothing in the middle to match my main monitor!

So I started researching programs that might allow me to define custom resolutions, but none of them will let me select any good middleground resolution. I was able to get access to some non "HiDPI" versions of the resolutions I'd like on the second monitor, but those look blurry without MacOS HiDPI scaling.

I've tried SwitchResX to try to define a custom resolution, but since both monitors share the same Vendor & Product ID, it doesn't let me define custom resolutions for the second monitor. And any attempts to do it for the first monitor (then maybe access them on the second) are met with "Not activated - invalid?"

So I tried the suggestions laid on here and here.

I know I've copied them correctly, because SwitchResX does show them in the "Custom Resolutions" section. They're just not selectable on either monitor. Same with RDM to try to select the custom resolution.

It almost appears as if a rotated monitor is treated specially by MacOS, but I just want some option to force a custom HiDPI resolution on that monitor, but I can't find anything that seems to fit what I'm trying to do.

So any suggestions to help me along the way? Would be greatly appreciated.