Macbook 13" unibody late 2008 driving 4K

[stephen2002]

I recently upgraded my monitor to a Dell U2718Q, which is a 4K screen. I have an older Macbook 13" aluminum unibody (late 2008) that I've updated over the years with an SSD, 4GB of RAM, and patched to Sierra. I mainly use for occasional testing of web sites in Safari and on the iOS SDK simulator so and still works fine for that so I'm not too interested in a new mac.

I hooked it up to the new monitor not expecting much, since the specs indicate a max resolution of 2560x1600, but I plugged it in via DisplayPort and was able to switch to a native 4K@30Hz. I can deal with the low frame rate. Of course everything was tiny. There is a scaled 1920x1080, which works, but everything is big. I was under the impression that MacOS supports rendering to an even higher resolution (scaled 2560x1440, so render to 5120x2880 and downsample) but all I see in the list is "2560x1440 (low resolution)", which looks a bit blurry as expected. Any idea how to enable the higher scaled resolution or if it would even be possible on this machine?

I don't get the "pick a scaling setting" with the "Larger Text" "More Space" options like from here.
https://support.apple.com/en-us/HT202471

 

[robvas]

The highest that machine supports at 60hz is 2560x1440

 

[stephen2002]

It defaults to 2560x1440 at 60Hz, I understand that is the maximum resolution at 60Hz, but it can do 4K at 30Hz. I'm not asking if I can get a higher refresh rate.

I'm wondering if there is some way to unlock the additional scaling modes beyond 1920x1080.

I was expecting a menu like the one here, but instead just get a list of resolutions when I pick "scaled".

 

[EugW]

Good to know. I had no idea my MacBook5,1 could get even 4Kp30.

If it could do HiDPI scaling that would be even better.

 

[robvas]

Have you tried SwitchResX?

 

[stephen2002]

I did but didn't have any luck with it. It offered more resolutions but 1920x1080 was still the highest HiDPI resolution available. I tried setting up a custom scaled resolution and that didn't appear to have any effect, however I'm not positive I set it up correctly as the UI is a bit obtuse.

Edit: I also tried the steps for adding resolutions on this thread without any luck. I think I'll just accept 1920x1080 HiDPI as the best it gets on this machine, unless anybody has other ideas.