MacBook Pro 13 — How to set HiDPI 2560x1440 resolution on 4K monitor

Note: Hints in this article apply to Macbook Pro 13 Mid 2014 with Intel Iris 1536 MB and LG 27UD88-W 4K

When I bought LG 27UD88-W 4K monitor and connected it to my MBP 13 only available HiDPI resolution was 1920x1080 what seems to be logic because it’s downscaled 3840 x 2160.

1920x1080 is definitely not an efficient workspace so I deciced to switch it to 2560x1440 but the screen was blurred and not crispy as I expected.

To fix this I spend a few days searching for solution as finally got the result.

1. Check your connector

HDMI cable is not capable to provide more than 30Hz. Replace it with DisplayPort — miniDisplayPort.

2. Disable SIP

You need to disable System Integrity Protection which allows you to modify system files: https://www.imore.com/how-turn-system-integrity-protection-macos

3. Override an EDID setting to force the RGB color space

Overriding EDID setting: https://www.mathewinkson.com/2013/03/force-rgb-mode-in-mac-os-x-to-fix-the-picture-quality-of-an-external-monitor

After this you’ll be able to switch between scaled hidpi resolutions but only with 30Hz. Reason: Apple decided to limit frequency to 30hz after update to Sierra.

4. Install SwitchResX and add custom resultion

After installing SwitchResX you will be able to manually increase monitor frequency. Follow the steps in tutorial: https://kandrejevs.com/blog/read/50/More-than-30Hz-on-Your-133-Macbook-Pro-and-4K-monitor

50Hz was the maximum frequency which I was able to set, above that value my monitor became black with warning about no signal.

mac-pixel-clock-patch-V2 — didn’t work

This patch is no longer compatible with newest MacOS versions and in my case resulted with the black screen and no display signal from monitor.