RE: U2518D, tearing, stuttering
Ok so fresh news. First of all something about HDR, when I use PS4, I can set it up (I turned it off, it is no point to turn it on on this monitor anyway) but when I connect PC (GTX960, Windows 7), I cannot set it up, it is grayed, probably because Windows 7 doesn't support HDR.
As for the videos, I created new videos with much better quality with DSLR (1080p/60FPS), and with pattern video, which show this problem very nicely so I start with this patterns:
Pattern - GTX960 - 2560x1440 - 0:11 , 0:37 , 1:04 , 1:30 , 1:56
Pattern - GTX960 - 1920x1080 - 0:21 , 0:59 , 1:36
and other videos:
GTX960 - 2560x1440 - 0:28 , 0:54 , 1:21 , 1:47 , 2:13 , 2:40 , 3:06
GTX960 - 1920x1080 - 0:35 , 1:12 , 1:49 , 2:26
PS4 - 1080p - 0:22 , 0:59 , 1:37 , 2:15
On the pattern video in 1920x1080 is very clear how the image is refreshed (tearing) from bottom to top. It is also clear, that this refresh occur in 2560x1440 as well, only much faster and because of that it looks more like stutter than tearing. Here is also some image sequence from video frame by frame:
Frame by Frame - 2560x1440
Frame by Frame - 1920x1080
Tearing at 1080p is 500 miliseconds long. At 1440p it is about 50 miliseconds long.
So just to be sure, I ordered another new U2518D. Surprisingly, my old monitor is Rev 00 and firmware version M2T101. The new one is Rev 01 and with firmware version M2T102. So it looked promising, but not for very long. Immediately in the first test, the new one did exact same thing like the old one. So two different units, two diferent revisions/firmware and same problem with tearing. I also tested it on the notebook Acer V17 Nitro with GTX860M and it did exact same thing. Also this is the list of complains from customers about this issue with this monitor on internet which I found:
And on some of this reviews from RyanH, John, Konew, ananymous and ZachcyB here:
So after all of this, I am confident to say, that I think that this is realy systemic problem with U2518D and it needs to be properly investigated and of course, it needs to be fixed.
Personaly, as I stated before, except this anoying issue I really like this monitor, so I returned only the new one (the new one has some problem with flickering on dark tones, which was clearly visible with inversion (pixel-walk) test) and the old one I keep for couple of months to see if Dell do something about this tearing issue, or at least bring out some official statement about this. If you don't fix this problem in 2-3 months, I will return this U2518D as well and buy something else, probably not from Dell...