Resolved cMP Retina/HiDPI Display Preferences?

[bookemdano]

Got a MVC flashed GeForce 750 Ti in my 4,1 and so far I'm very happy. Now I can keep my 4K monitor on/in DP1.2 mode and be able to successfully boot and see the boot screen.

However, an issue remains that I also experienced with my previous 7950 setup--OS X assumes my setup isn't HiDPI capable. I go into Display Preferences and instead of seeing the slider of HiDPI options I see the old-style list of resolutions (none of which are HiDPI).

I bought the helper app "Display Menu" which does allow me to set HiDPI resolutions. I've bookmarked a few favorites.

But every time I reboot, the resolution resets to 3840x2160 and I have to manually change back to the HiDPI res. This is in contrast to my rMBP which does remember my HiDPI resolution choice and maintains it through reboots. So my guess is that the two issues are related.

My questions to the gurus here:

1. Is there any way to tell OS X on my cMP that the machine is HiDPI capable and to offer up the HiDPI GUI elements in Display Preferences?

2. If solving #1 doesn't also fix the problem of reverting to 3840x2160 after each reboot, are there any other solutions to that?

Apologies if this is covered in other threads. I did search a bit but didn't find a whole lot pertaining to this exact issue.

Edit: I should add that I'm running 10.11.4. Haven't tried to see if behavior is any different under Yosemite.

 

[h9826790]

Can you see all the HiDPi resolution if you hold option and then click "scaled"?

 

[bookemdano]

Can you see all the HiDPi resolution if you hold option and then click "scaled"?
View attachment 626829

Yes, except they are notated differently than in your screenshot. On my cMP the resolutions say "(low resolution)" next to them in the list. If I option-click Scaled then I get the HiDPI resolutions listed in the list as well. They don't say "(HiDPI)" like in your screenshot. There is no designator, but when I choose one it is obvious that they are using the OS X scaling (versus the "low resolution" choice is using the monitor's scaling). Here's an example of what I see if I option-click:

2460 x 1440 (low resolution)
2460 x 1440

Do only Apple's specific Retina Macs get the UI with the Larger Text/Default/More Space buttons? If so, that's fine. But why is OS X resetting to 3840x2160 every time I reboot?

 

[h9826790]

AFAIK, that slider is only for retina Mac. But it should not reset to 3840x2160 on every reboot, OSX should able to remember your option, especially if you choose that from system preference.

 

[bookemdano]

AFAIK, that slider is only for retina Mac. But it should not reset to 3840x2160 on every reboot, OSX should able to remember your option, especially if you choose that from system preference.

Bingo! Changing the resolution directly from System Preferences->Displays was the answer. It seems this is just a bug/characteristic of Display Menu--it will not maintain any resolution you choose via its menu after reboot. But setting it via system preferences it does maintain.

Thank you h9826790. I really appreciate you taking the time to answer so many questions here and share your expertise.