980 Ti / MacPro 3.1 - 4k image too small, can't see recovery mode screen

[koomatai]

Just got a Geforce 980 Ti and 4k tv for my old (not Hack) MacPro 2008. 4k image is too small, and no controls for scaling, so trying to use SwitchResX, but it now says no custom anything in OSX 10.11.6 (can't update further) without first disabling SIP which seems to require CMD R at boot. Unfortunately, no screen comes up when I do this.



Is this because the 980Ti can't display the recovery mode boot screen? It is "mac flashed", and does display option boot for drive selection. Is something else going on, or am I going to need to reinstall the factory card just to access recovery mode just to disable SIP?



Am I missing another utility or simpler way I can get scaling options or other way to fix the display?

 

[Gen_]

If it can see the option boot it can see everything: option boot is EFI and mac flashed cards are only flashed specifically to see EFI. It is more likely that a 2008 Mac does not have a recovery drive, especially if it has not been wiped for years. You can try CMD SHIFT R for Internet Recovery, which is your only option at this point. Why is what is bugging me.

Your Scaling options are not a factor of your card. They are a factor of your display. Scaling is called HiDPi in Apple land.

Put the following in terminal with your password after to enable Scaling on your display. Make sure you do this with your display and GPU enabled and set as primary. The result will be saved to that display but may be reset with the swap of a GPU or display.

sudo defaults write /Library/Preferences/com.apple.windowserver.plist DisplayResolutionEnabled -bool true


Dont do this in recovery or safe mode, just as your normal logged in user account.