> This aligns with our findings. The M4/M5 DCP firmware implements a conservative framebuffer pre-allocation strategy that:

> Caps the HiDPI backing store to approximately 1.75x the native resolution (6720x3780 for 3840x2160 native), rather than the 2.0x needed for full HiDPI (7680x4320)

So, that could be an off by one bug? That might be testable by tweaking the system to think the display supports an even higher resolution.

Also, instead of messing with the Display Override Plist, patching drivers, etc, did they try using the “Advanced…” button in the “Displays” UI? They don’t mention they did.

For me (with a 27 inch 4K monitor not on M4 or M5) that replaces the 5-way choice by one with a list of 11 choices. With the then appearing “Show all resolutions” toggle, that becomes 18.

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smcleod 2 days ago | parent [-]

I tried quite a few things in the "Advanced" section of BetterDisplay - is there something specifically you're suggesting?

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Someone 2 days ago | parent [-]

I’m not talking of BetterDisplay. I’m talking about Apple’s UI. Scroll down the content of the “Displays” pane, and you find a row of buttons “Advanced…”, “Night Shift…” and “?”

	▲	mmcnl a day ago \| parent [-]
		Ofcourse this has been tried, the highest possible resolution with HiDPI is limited to what the article says.