Displayport and powersaving problems

[idata]

I have a Z77 chipset Asus P8Z77-V Premium motherboard with Displayport, HDMI and Thunderbolt video output. I recently purchased a new monitor LG 24GM77-B which can run at 144Hz or 120Hz with a strobe backlight which I find best as it significantly lowers blurring which I find intolerable on the majority of LCD monitors.

I have started using Displayport as it provides the 120Hz that I need, whereas HDMI only provides 60Hz however I am having big problems with the display going totally blank at random times when power saving. It will work find after rebooting for hours and then the display will power down and refuse to awaken. No mouse movement or keyboard input will awaken the display. I have powered down the display pulled the plug but it refuses to resume and show a display.

I removed the Intel graphics driver that was installed and installed the latest. I even did a driver clean to remove all remnants of the old Intel drivers but it made no difference.

I do also have one of the HDMI connectors on the monitor connected to the HDMI port on the motherboard and I have set the display to mirror to the two connectors. Now since doing this I can access the HDMI connected display and it does show a picture when the displayport connector just powers down the monitor so there is at least one display working. It's just the displayport which is a problem.

I never had these problems when using DVI-D on my older X48 motherboard with nVidia graphics card, it is only displayport which has a problem. I have checked the cable and it seems okay and I think it was displayport pin 20 which needs to be not connected which did seem to cause some people problems. I did try and test for a connection but I cannot be certain that it tested successfully due to having to test it with a piece of wire into the connectors to test for a circuit. The cable was totally disconnected when I did this!

The Intel driver shows as 10.18.10.4425 in device manager and about 4 months old. This is with Windows 7 x64 SP1.

I am stuck as I keep having to switch to HDMI with only 60Hz as the displayport keeps causing problems. I do also have some problems when booting my PC as the displayport seems very flakey during booting too. It only seems to work when inside windows on the windows loading/logo screen. I do have windows on a boot menu and that frequently does not show on displayport but does on HDMI/DVI-D. It's as if the driver enables the display which seems disabled earlier.

As I post this I am having to use HDMI as the displayport has failed yet again.

[idata]

Hi lister.of.smeg,

The issues that you are experiencing with the Display Port are related to the refresh rate that you are using on your TV. The 3rd gen processor has embedded graphics HD 4000, and the maximum resolution is 2560 x 1600 using DisplayPort, HDMI or VGA with a maximum refresh rate of 60Hz. Your TV is pushing up the graphics card and it will fail sooner or later. You can find more details of the graphics for 3rd Gen HD Graphics athttps://software.intel.com/en-us/articles/3rd-gen-hd-graphics-quick-reference-guide https://software.intel.com/en-us/articles/3rd-gen-hd-graphics-quick-reference-guide Regards,Mike C

[idata]

I am only using 1920x1080p so I do not see how I can be pushing things too far even though I am using 120Hz. It is a native supported resolution and refresh rate in the Intel graphics control panel. No custom resolution was created in order to do that refresh rate and Displayport 1.1 should support that fine. However it does not seem to support 144Hz which is the maximum that my monitor is meant to support. I used that fine on my other system with DVI-D.

I have just noticed that I did not have the monitor driver installed so I have installed that. There was also something called calibrize that was running when I booted which was supposed to load monitor colour profiles which was not needed so I have terminated and uninstalled that to see if it makes any difference.

[idata]

Hi lister.of.smeg,

Thank you for your update and workaround. I would appreciate if you can provide me your findings. Regards,Mike C

[idata]

I have not experienced the power saving problem since I made the changes that I did. However I am still having problems with no display output on Displayport when I boot my PC. I do not get any display until the blue Windows welcome screen. However I do get a display if I switch to HDMI. The displayport refresh rate while in the bios and prior to the windows drivers loading should be 60Hz and I am sure that it cannot be set to 120Hz before windows.

No display on displayport while in the bios but there is when switching to HDMI.

Why am I not getting any display from the displayport connection until I am inside windows?

[idata]

Hi lister.of.smeg,

I believe it is a BIOS setting issue. I suggest you get into the BIOS and change the primary video port, usually it provides with the option for every port or auto option. Regards,Mike C