GTX 750, Sierra, Black screen after sleep

[muratyilmaz]

darkwake=0 solved my problem

I tried MacPro 5,1 as well as iMac 14,2 Mac Pro definition works well for I7 turbo mode my CPU can go up to 3900 but on iMac definition system stuck with 3500 turbo mode is not enabled. I have to put computer in to sleep and waken up than only works.

 

[D-vise]

darkwake=0 solved my problem

I tried MacPro 5,1 as well as iMac 14,2 Mac Pro definition works well for I7 turbo mode my CPU can go up to 3900 but on iMac definition system stuck with 3500 turbo mode is not enabled. I have to put computer in to sleep and waken up than only works.

I have got the same problem as discussed in this thread: my screen stays black after sleep. But this problem only occurs on one of two nearly identical computers:
- ASUS Z170I Pro Gaming, Zotac NVidia GTX 750 (Zone Edition), 16 GB RAM/ 32 GB RAM, Crucial mx300 SSD

The displays are different:
- one is an Apple Cinema Display (LED/24)
- the other is a Dell P2715Q (4K)

Both configurations use DisplayPort, however, one system uses the DisplayPort with 4K@60Hz, which is the system which does not really wake up its display. I have tried HDMI (4K@30Hz), but that does not work either.

Another difference is the ASUS BIOS revision number: the working configuration has 1809, the non-working one has 2002. I have tried to downgrade, but the BIOS updater does not let me so.

 

[Fl0r!an]

Can you swap displays to rule the different BIOS revision out?

I've heard about some Dell screens having trouble to wake from (display) sleep in the past, maybe your P2715Q is one of them?

 

[D-vise]

Thank you so much for your hint.

It was in fact the Dell Display (P2715Q). Dell has an entry in their knowledge base:
http://www.dell.com/support/Article/de/de/debsdt1/SLN296015/EN

The Dell solution is to use to change the "MST" setting to "Secondary" on the display side. This make the display think it is a daisy chained display. It will then use the DP 1.1 protocol instead of 1.2; 4K@60Hz are not possible then, however 4K@30Hz do work.

 

[robaird]

Thanks D-vise! Was having to cycle power on Dell U2715H each time computer woke from sleep after I switched to DP 1.2--switching monitor settings back to DP 1.1 fixed it.