1 Reply Latest reply on Sep 23, 2014 12:38 PM by Robert_U

    Clevo W740SU Notebook with Intel 5200 Iris Pro @ 4k 60hz, popping, flickering and blackouts




      I have the above notebook with Windows 8.1 64 bit connected to a Philips Brilliance 288p 4k screen (3840 x 2160@60 hz, displayport 1.2 mode selected in the on-screen menu of the monitor). I have the latest bios for the notebook (1.03.04) and use the latest graphics drivers from intel ( from 8/29/2014. I connect the monitor using a mini displayport to displayport cable (manufactured by Deltaco, type DP-1110).


      The problem is that I get occasional popping sounds, flickering (and other glitches) and even blackouts lasting a couple of seconds. These problems were worse with earlier version of Intel drivers, but still continue with the latest drivers. The same problems occur if chose to use 3840 x 2160 @ 59hz or even 30hz (which I prefer not to do).


      Could the problem be that the signal strength from the Intel 5200 Iris Pro is not sufficient? This, of course, is speculation from my part but I have definitely noticed that the receipt of a text message by my Iphone 5C can induce a black out lasting a few seconds. I will definitely try to find a higher quality mini DP 1.2 cable (already tried another cable, did not help)... As the problems were worse with the earlier drivers, it would seem to me that this cannot only be a cable issue.


      AN UPDATE: For some reason the problems seem to disappear if go into the Intel graphics control panel and choose to extend the desktop from the 4k screen (as primary display) to the laptop screen, i.e. the signal seems stable when both displays are on at the same time.


      UPDATE II: The signal is more stable when extending the desktop to the laptop screen as well, but unfortunately  the problem does not disappear. I still get occasional popping sounds and blackouts (accompanied by a loud popping sound). On some occasions the screen does not recover from a blackout ("no video signal, enter sleep mode") - to get the picture back I have to remove and reinsert the mini DP cable. The OEM graphics drivers from Clevo are from January 2014 ( and do not seem to support 4k @ 60hz, so they offer no solution to the problem. After the most recent black out, after having removed and reinserted the mini DP cable, the left half of the screen was totally garbeled. This was corrected after I turned the monitor and off.


      I have ordered a (presumably high quality) mini DP cable manufactured by Lenovo, I will report back once I get it.


      UPDATE III: I have now tested the mini DP to DP cable from Lenovo, and I am happy to report that the problems have disappeared (no popping, no glitches, no blackouts)! So the culprit were the generic mini DP to DP cables atfter all.


      UPDATE IV: Unfortunately, while the new higher quality cable did help, I still get the occasional blackout (accompanied by loud popping sound).