Recently I bought a Dell U2518D monitor after a lot of research because I have some specific features in mind, after all I bought it for productivity and occasional entertainment. Well my research maybe wasn't so good because now I see some problems with the panel.
First the good things:
1. Sharp and beautiful picture, rich color and good 2k resolution.
2. sRGB and Adobe RGB color gamut.
4. No FRC, pure 8 bit.
5. REC 709(nice to have it, didn't try it yet).
6. HDR 10(nice to have it, didn't try it yet).
7. Rich connectivity options.
1. Occasional vertical and horizontal screen tearing(MAIN deal breaker).
2. Backlight bleed(not so big of a deal but it's annoying).
Connection via HDMI, screen tearing appear in both 1.4 and 2.0 setup. Used guide from here to change type of input to switch between modes.
Source is UHD 630 on board integrated graphics of i5-8600k.
Steps applied to prevent screen tearing:
1. Disable SmartHDR in OSD: No effect.
2. Change Response time, Normal to Fast: No effect.
3. Update Intel integrated graphics driver to latest available: Not fixed the issue but instead reduced to half at the moment.
4. Switch to HDMI 2.0 from 1.4: Not fixed the issue but reduced the tearing which is strange because the port of my motherboard is HDMI 1.4 compatible and UHD 630 support HDMI 1.4.
5. Disabled all UHD 630 picture enhancements: No effect.
6. Firmware of monitor is latest: M2T103.
1. Players > Pot player watching movies or clips: Mainly vertical tearing and occasional horizontal tearing. Vertical tearing was more prominent in fast paced scenes or rapid change in brightness.
2. Games > World of tanks: At first heavy screen tearing with no Vsync enabled. After Vsync was enabled pretty much no tearing at all just from time to time.
So if any solution is available I am going to be very happy.
The fact that installing the latest Intel UHD 630 driver lessened the issue points to the low end onboard Intel GPU or its drivers as the culprit. To verify this, can you test the U2518D on another PC that has a higher ended Nvidia or AMD discrete video card to see if the issues follow the U2518D?