I have two U2417H monitors daisy chained via display port and they both flicker intermittently for at least a second anywhere between 5 to 10 minutes randomly. I have a Dell Precision M6800 laptop and dock. I'm using the factory provided DP to mini DP cords and power cords.
From my docking station I connect one DP to mini DP cable to the first monitor. Then I connect the second cable from the DP out to mini DP in on the second monitor.
I've enabled MST on the 1st monitor in the chain and disabled it on the second monitor. I've tried disabling Display Port 1.2 and that didn't help.
If I disconnnect the second U2417H monitor and only use the first I do not have this issue.
I have an NVIDIA Quadro K3100M graphics card installed by Dell. I've updated all Dell and NVIDIA drivers with no success.
I'm have the same issue. So far I haven't been able to find any answers. I've ordered a new DP-DP cable and a HDMI cable to test. From what I've seen online, it seems like MST (DisplayPort 1.2) on these monitors, as well as the previous versions of this line, is just ***. I've tried two different video cards, two different power supplies with no difference (although the flickering seemed a little less often with the better video card). Additionally, I'm also seeing an issue where my monitors don't seem to wake up from sleeping and/or they just show a black screen. When booting, I sometimes do not see anything after the POST screens - it's just black thereafter - and this is always with MST turned on. I'll report back with what I find when the new cables arrive, but I kind of doubt that'll change anything.
I did try plugging HDMI and DP into Monitor 1, setting Monitor 1 to use HDMI, and then daisy-chaining Monitor 2 via DP, and that actually seemed to work.
I ordered a VDI to mini DP converter cord to try. Not even a single display would work that way. I tried HDMI directly from my laptop and it worked but my docking station doesn't have an HDMI port only VDI, DP, and VGA. Dell sent me one new replacement monitor under warranty which didn't help.
My ticket got escalated to upper support and a nice woman explained to me that the firmware has been updated and the issue is supposed to be resolved. She explained that if the serial number ends in a A01 that is a revision 1 monitor and a -A02 is a revision 2 monitor.
Around the same time I happened to receive a refurbished monitor to replace my second and it's an A02 (my first replacement still being an A01). I put the A02 first in the chain and one or the other only blinks about once or twice per day now. I requested that both existing monitors be replaced by new A02 monitors and not refurbs for my time invested in this, my trouble and peace of mind. Hopefully that will resolve the issues.
I have two U2415 daisy chained and ran into the same issues many reported with 1) display flickering 2) second monitor fails to go into sleep mode. The flickering was only a few times a day in the beginning and progressed to almost constantly flickering (once every ten or so seconds).
After some tinkering around, found the culprit to be the cable connecting the first and second monitor (DP to DP). Both problems solved after switching to a different cable. (My monitor doesn't come with any DP cable)
It seems the monitors are very picky with the quality of the connecting cable. Even the 'bad' cable is supposed to be high quality and dp 1.2 rated but I guess it wasn't good enough.
Suggest buying the best cable you can find for the job and get a spare one from another manufacturer just in case.
The U2415 shipped with the mDP to DP cable? Did you test the daisy chain using the provided cables with the U2415?
When looking at the bottom rear of the U2415 left to right =
Power, HDMI, HDMI, #4 DP in, #5 mDP in, #6 DP Out
Computer DP out --> U2415 DP to mDP cable --> #1 U2415 mDP in (Port 5) (DP 1.2 Enabled in OSD)
#1 U2415 DP out (Port 6) --> U2415 DP to mDP cable --> #2 U2415 mDP in (Port 5) (DP 1.2 Disabled in OSD)