Displayport issues on HP Z38c curved monitor

[milleniumaire]

Since I purchased my Z38c curved monitor in late April I have been unable to get it to work properly using displayport.  My desktop and laptop both support displayport 1.2, which is the same version supported by the monitor.  When in use, the monitor screen blacks out for a second or so on a regular basis and also I get flashing horizontal lines.  HP support have been unable to troubleshoot the issue and have simply arranged for the monitor to be replaced, so I'm now on my 3rd monitor and the issue still occurs!

If I connect the monitor to my desktop using HDMI then I don't see the issue, however, my PC only supports HDMI 1.4, whereas the monitor supports HDMI 2.0.  As a result of my system using HDMI 1.4, I can't get the full refresh rate of 60Hz, only 30Hz at the native resolution (3840 x 1600) over HDMI.  This isn't acceptable to me, I need the monitor to run at 60Hz.

So, despite trying 3 different Z38c monitors, 3 different displayport cables (including the one that came with the monitor and a brand new 8K, v1.4 capable version), the latest video drivers (dated July), 2 different graphics cards and a different machine (my HP Zbook 15 G3), no configuration will give me a working setup when using displayport.

I would be interested in hearing from anyone else who is running a HP Z38c monitor and if they are using displayport on Windows 10.

Thanks.

[milleniumaire · Accepted solution]

A disappointing lack of response from this HP forum.

Still, I shall update it with a solution I found.

I purchased a Displayport (v1.2) to HDMI (v2.0) adapter.  This plugged into the displayport socket on my PC and then then one end of a 4K rated HDMI cable was plugged into the other end of the adapter, with the other end of the HDMI cable plugged into the Z38c monitor.

This works and I now get 3840x1600 @ 60Hz.

This is yet another indication that the displayport on the Z38c product does not work correctly, not just on the current monitor I have, but also on the previous 2 monitors I tried, suggesting there is an issue with this product that HP need to investigate.

I say this because when ANYTHING is plugged into the Z38c displayport I get blackouts and horizontal flashing.  This adapter is plugged into my PC displayport and clearly the signal from that works perfectly otherwise I would be getting issues through the HDMI cable also.