Just got a P2815Q f (not sure what the lower case "f" letter means), and I can't get it run at 1920x1080 60Hz. I have the P2715Q that works great. That's the reason I got the P2815Q. I'm using the same cable (mDP to DP), same laptop (MacBook Pro 15" 2018).
The image attached is for the smooth & nice working piece, the other one is the same but 30Hz.
Policy statement about non-tested Apple =
Check the Dell validated operating system drivers listed. The P2815Q was not tested/validated by Dell with the Apple proprietary hardware and software. All we provided were true Windows PC testing and drivers. We can give you "best guess" support but you should also post this issue on the Apple Forum to get their opinion on troubleshooting.
Were these two Dell monitors purchased directly from Dell?
You can see here that there is only one P2815Q. The model name is P2815Q. The regulatory name is P2815Q f.
What are both Dell monitor 20 digit S/N?
My working one (60Hz) is P2715Q, and my non working one (30Hz) is P2815Q. Both of them purchased directly from a certified reseller of Dell. You are right. What are both monitor 20 digit S/N?
- working P2715Q S/N? - CN-0V48W2-74445-733-C5FL
- non-working P2815Q S/N? - CN-0WJJGR-72872-442-CL4M
Technically, none of our cabling was validated for the Apple TB3 ports.
P2715Q built on March 3, 2017
P2815Q built on April 2, 2014
* Turn both monitors and the MacBook Pro off
* Disconnect all monitor cables from the MacBook Pro
* Open the MacBook Pro lid
* Turn the MacBook Pro on
* Disconnect EVERY cable from the P2815Q
* Press and hold in the P2815Q power button for 10 seconds
* Reconnect the power cable to the P2815Q
* Connect only the P2815Q to the MacBook Pro =
MacBook Pro TB3 --> P2815Q mDP to DP cable --> P2815Q DP in port
* Turn the P2815Q on. If you still cannot get 3840x2160 60Hz, purchase a true TB3 to DP cable