HP z420 incidence of MSTS: Mysterious Screen Tearing Syndrome

[BambiBoomZ]

Friends of the Z,

I've reached an impasse with HP z420_3:

HP z420_3: (2015) (R11) Xeon E5-1650 v2 (6C@ 4.3GHz) / z420 Liquid cooling / 32GB (HP/Samsung 4X 8GB DDR3-1866 ECC registered) / NVIDIA GeForce GTX 1060 6GB/ Samsung 860 EVO 500GB + HGST 4TB / ASUS Essence STX / Logitech z2300 2.1 / 600W PSU > Windows 7 Professional 64-bit (HP OEM ) > Samsung 40" 4K

[Passmark System Rating: = 5644 / CPU = 15293 / 2D = 847 / 3D = 10953 / Mem = 2997 Disk = 4858 /Single Thread Mark = 2384 [6.27.19]

The problem is that this system, the 4K display on any streaming, when there is the slightest motion exhibits strong screen tearing. this appears only on streamed media and not on DVD or stored media playback. The internet service by the way is "100MB/s".

I've tried every combination that makes sense.  using the NVIIDIA control panel within Windows 7 Control Panel, There have been experiments with Vsync,  both global and application -related, latency controls, reducing resolution, lower frame rates, even power management, following procedures on YousTubey and gaming sites, but nothing improves it much.  Actually, the NVIDIA default settings have among the best results. Last evening, I tried changing the GTX 1060 6GB for a GTX 1070 Ti 8GB but that = the same situation. The one thing I haven't done is try very low frame rates.

This is not affecting work, but this system has a high proportion of streaming use.  It's disappointing to have a quite high-level performing system- in the top 10 of over 1,400 Passmark z420 system ratings that has such a visible performance deficit.

Any ideas welcomed!

BambiBoomZ

[DGroves]

if it only has issues when using the network as a transmission device and not when playing 4k locally off the z420 you need to look at the network itself,.. as a quick test i would try streaming a 4k file locally from a local system to the z420 and vice versa bypassing the router and firewall

and if the local 4k transmission works fine,  look at the router and see if you can prioritize the 4k packets, or try bypassing the router

if you have access to a network analyzer, use it to determine if any issues are on your network this is really the only  way your going to be able to see what's going on

[Brian1965]

Hi BambiBoomZ,

Couple of questions just to clarify;

1. Are you using a VPN?

2. I assume you are viewing with a web browser? Have you tried different browsers, e.g. Firefox, Chrome, Opera, etc.

3. Are you streaming via LAN or WLAN?

4. Have tried streaming any of the 4K videos on youtube?

Since you can play local 4K videos without any issues then it would suggest your 4K display and your chosen connection to the display are working fine (i.e. DP or HDMI), (and also the nVidia driver appears to be working okay).

[BambiBoomZ]

Brian1965,

Thank you for your reply- very good points.

1.  Yes, I'm running a VPN.  I've tried viewing the same videos with the VPN off- no effect.

2.  Yes, I've tried Firefox, Chrome, and Tor.

3.  I've tried quite a number of 4K videos on YouTubey.  The thing is, a number of these are very placid, nature scenes with so little motion that they do not trigger the screen tearing.

4. I've tried two different HDMI to HDMI cables, a DisplayPort to HDMI, and a DP to HDMI adapter to HDMI cable. No improvement,

5.  I tried 2560 and 1080P resolutions and 24FPS instead of 60FPS.  The resolution had no effect and actually the 60FPS refresh was interestingly better than the lower rates. I'm still working on the implications of that.

6.  The GTX 1070 Ti 8GB from z620_2 was substituted for the GTX 1060 6GB- no improvement.

Last evening, I used Speedtest (again) to verify that the connection download speed equaled or exceeded the 100MB/s service rating.  Then  I changed the TV connection from z420 _3 to a direct connection from the network switch to the TV and there was no screen tearing.  This is good news, but as the sound is changed to the internal TV systems, from the ASUS STX / Logitech 2300 2.1 sound system, it's not total solution; the video may be 4K, but the sound is greatly degraded. I also far prefer having the computer keyboard to search and control instead of pecking it out with the arrow controls on a small remote. 

My  assumption is that the GTX 1060 6GB- as fast as it is, and the processing of the signal is causing the tearing, but that doesn't explain the fact that when running Blu-Ray or material resident on the HD do not have the tearing.

So, some progress, but the exact underlying problem is still not clear.

There is another impending potential disaster as z420_3 may be moved to a room in which it will need to run on WiFi.

BambiBoomZ