Mac Pro5,1/Mojave/Sapphire RX850 display won't sleep

[Cave Man]

I upgraded to this card and have my 27" ACD connected to it with a DP to MDP adapter. Screen saver comes on, but the display does not shut off. Anyone know of a fix for this?

Thanks!

 

[kasuja00]

Does your Mac Pro go to sleep mode regularly?

 

[bookemdano]

I doubt it's related to the video card. Hit Command-Space and type activity monitor, hit enter and then on the activity monitor screen, go to the Energy tab. Click on the column header for "Preventing Sleep" and see what, if anything says "Yes" in that column.

There are also some terminal commands that can help figure out sleep issues but that's a good first step.

Just realized you were referring to the monitor sleeping, not the Mac. Do you have the "turn display off after" setting enabled in System Preferences > Energy Saver?

 

[h9826790]

I upgraded to this card and have my 27" ACD connected to it with a DP to MDP adapter. Screen saver comes on, but the display does not shut off. Anyone know of a fix for this?

Thanks!

Did you try re-boot / logout and login yet?

Assume you have correct setting in system preference

 

[Cave Man]

Does your Mac Pro go to sleep mode regularly?

Just realized you were referring to the monitor sleeping, not the Mac. Do you have the "turn display off after" setting enabled in System Preferences > Energy Saver?

Did you try re-boot / logout and login yet? Assume you have correct setting in system preference

Yes, the display is set to sleep after 15 min and the computer is set to sleep after 1 hour of inactivity. Yes, it's been rebooted.

 

[bookemdano]

Yes, the display is set to sleep after 15 min and the computer is set to sleep after 1 hour of inactivity. Yes, it's been rebooted.

Were you using this monitor and cable with a different GPU before getting the 580? That is to say, is the 580 the only variable that changed (aside from installing Mojave)? And was Mojave a clean install or upgrade install?

Edit: Did you buy the card brand-new in box? Or was it purchased used?

 

[Cave Man]

Were you using this monitor and cable with a different GPU before getting the 580? That is to say, is the 580 the only variable that changed (aside from installing Mojave)? And was Mojave a clean install or upgrade install?

Edit: Did you buy the card brand-new in box? Or was it purchased used?

Card was new and the only other variable is the DP to MDP adapter from the ACD to the card.

 

[bookemdano]

Where did you get this adapter? I would think that's the first thing to suspect. Rather than an adapter, maybe just look for a mDP to DP cable.

 

[h9826790]

Where did you get this adapter? I would think that's the first thing to suspect. Rather than an adapter, maybe just look for a mDP to DP cable.

The cable is attached to the ACD, so, normal MDP to DP cable won’t work. It has to use adaptor.

 

[bookemdano]

Ahh, what a regrettable move by Apple. Captive cables suck!

OP, you didn't answer whether this was an upgrade or clean install of Mojave. If an upgrade, and you have the time and means to test a clean install that would be instructive. You could also clean install High Sierra to rule out a new issue with Mojave.

Barring that, since adapters are cheap, I'd try another one (of a different make/design). Please update the thread with your progress.