Community
cancel
Showing results for 
Search instead for 
Did you mean: 
Maurits
Beginner
583 Views

Intel UHD 620 bad contrast ghosting on monitors

Hello

I recently got a Lenovo T590 with a UHD 620. And while the screen works well, my external screens (Samsung 32", but only 1080p) look terrible. Horrible contrast artifacts on sharp transitions like text, especially if the transition is to/from mid to/from either high or low intensity.
It looked perfect on my previous Laptop with Intel HD 5500

Its currently on driver 27.20.100.8673, pre-release from Intel
I also tried the most recent stable release from Intel. And of course the offical one from Lenovo Vantage, which was a 26.something version

I played with all the settings on monitor and PC. Gamma, brigthness, contrast, back and forth and also reset to factory defaults.
Makes no difference

Also, I tried both the build in HDMI, the Displayport from the official Lenovo docking station via USB-C, and HDMI via a cheap china USB docking station. And multiple cables. All the same.


Its somehow related to the combination of the UHD620 and the monitor. Two other Laptops, with also Intel Chipsets, work perfectly on these monitors. I tried one other Acer 27" monitor, it works well on this UHD 620 based laptop. Somehow the combination is not good. And I have two of these 32" screens, so I'd like to keep them. (The Acer was borrowed for this test)


Somehow, I think the clue is in datastream and its the timings. Pixel clock, porches, and all that stuff. For the same resolutions, this UHD620 is sending different timings then the older HD5500. Probably has to do with the EDID that the monitor sends.

* Does anyone have any suggestions
* Are there any diagnostics utilities what timings are used (for both HD5500 and UHD620) when a monitor is connected
* Or to find out what EDID is send by the monitor
* And then, are the any utilities for tweak the timings (transplant the HD5500 to the UDH60?

Thanks

Some images from monitor with the Dell/Intel HD5500 and the Lenovo-UHD620 for comparison attached. They are zoomed in photo's, so some Moiré  effects, but its about the contrast ghosting.

0 Kudos
11 Replies
IntelSupport
Community Manager
572 Views

Hello Maurits,


Thank you for posting on the Intel* Community Forums.


To better assist you, please provide me with the below reports:


Please run the following tool in Windows* and attach the report generated. 

  

Intel® System Support Utility (Intel® SSU) 

 

  • Intel® SSU Download
  • Open the application and click on "Scan" to see the system and device information. By default, Intel® SSU will take you to the "Summary View". 
  • Click on the menu where it says "Summary" to change to "Detailed View". 
  • To save your scan, click on "Next", then "Save". 


With the external display connected, provide the Intel* Graphics Command Center report:

 

>Go to the Intel Graphics Command Center

>Support

>System Diagnostic

>Generate report.

>Attach the report file.


Best regards,

Maria R.

Intel Customer Support Technician


Maurits
Beginner
545 Views

Thanks for your response, attached the reports.

I note it reports the screen is connected through DisplayPort. While it may be so that some laptop internal DisplayPort to HDMI adapted exists, or maybe DisplayPort and HDMI are somehow electrically equivalent, the actual connection is currently through HDMI on the side of the Laptop

Mind though, even if I use the true DisplayPort on the Lenovo docking station, the result is the same.


Also, I do not want to confuse things, so I did not attach, but if you want, I can also add reports of the correctly working Intel HD5500 chipset?

Thanks

n_scott_pearson
Super User Retired Employee
505 Views

Unless they are using native HDMI support (which is usually not the case since only HDMI 1.4 possible), they will be outputting in DisplayPort format and using a LSPcon IC to convert from DisplayPort to HDMI 2.0 format.

Now, the HDMI quality can be affected by the conversion that is performed by the LCPcon IC. This is done in firmware on the IC. Have you checked to see whether Lenovo has released updated firmware for this IC?

...S

Maurits
Beginner
488 Views

I am not sure how to check. I ran all Lenovo Vanatage updates. including all optional. But such chip is of course nowhere mentioned. Also not listed in the Windows device manager. And next I ran the Graphics update from Intel directly to push the version beyond Lenovo.

Also, somewhat counter to your point (though hard to be sure): The issue also occurs on docking station which is a true DisplayPort output, so no such Lenovo chip would be used. And when connected to a different Acer monitor (not mine, borrowed for this test) it is also via HDMI, thus via such chip, but the output is good. 

So unless you can give a few more hints how to check this conversion chip firmware, my hope is on Maria R. from Intel Customer Support 

 

BTW: I also already asked Lenovo. 

 

EDIT: reading up on this LSPcon chip, I see it is for HDR signals. My screens are -not- HDR capable, and Windows 10 claims HDR is not active on this screen. 

n_scott_pearson
Super User Retired Employee
479 Views

Oh, you won't see that chip from Device Manager; it isn't visible to the processor as an enumerable device. Also, it is NOT just for HDR; it is, in this case, for converting from DP to HDMI. As for whether such an IC is present, I can tell you that this is definitely the case (you wouldn't see it saying its in DP mode otherwise).

As for checking for firmware updates, this would need to be something between you and Lenovo. If they do not have any updates posted, call their support people - you know, the folks you should have contacted first anyway.

How is this docking station connected to the laptop? Unless it is via USB-C (for DP Alt. Mode) or perhaps some custom connector (Lenovo is infamous for using proprietary connectors, forcing you to purchase your dock from them), it is not a processor DP channel that is exposing this DP connector. 

...S

Maria_R_Intel
Moderator
437 Views

Hello Maurits,


The information provided by the community member is correct, and we would also like to know how is the docking station connected to the laptop? Can you please, provide the specific Docking model?


Also, can you please specify, does the issue persists if you use straight connections? HDMI* from PC to HDMI* on the external display or DisplayPort* to DisplayPort*.?


Best regards, 

Maria R.  

Intel Customer Support Technician 


Maurits
Beginner
388 Views

Hi

The official docking station is a branded Lenovo, model name "Thinkpad USB-C dock" and model number DK1633. It also has barcode with "TYPE 40A9"  and thus seems to be this one

 

It is connected through USB-C, which I suppose is making use of the USB-C thunderbold protocol
Wiring is:
Laptop USB-C out => Docking DisplayPort out => external DisplayPort to HDMI dongle (1080p capable) => Samsung HDMI in

 

Direct connections giving the exact same image:
Laptop HDMI out => Samsung HDMI in

 

I also have a cheap China USB-C dock, I assume also using the thunderbold:
Laptop USB-C out => China Docking HDMI out => Samsung HDMI in

 

Unfortunately, I do not have any Monitor with DisplayPort input to try a true direct connection


As mentioned, I did try a Acer 27" monitor with HDMI in, which gave a good image, I suspect that monitor did have HDR capability, but it was borrowed. If useful, I can attempt to reborrow it to check.
Laptop HDMI out => Acer HDMI in

 

Thanks again for taking this issue into proper consideration. These are 32" monitors, so they are not that cheap to replace. And to restate, they worked very well on HD5500. Also, my eyes would not see 4K anyway.

 

PS/Edit: using above info, I updated firmware on the docking station. It did not make a difference though.

Maurits
Beginner
388 Views

Hi. 

Not sure what happened, I answered, and the answer is not appearing.
Oh well, just do it again. Apologies if it now appears twice.

 

Docking station is a "Thinkpad USB-C Dock"  TYPE 40A9. I also just now updated its firmware, but that did not help.

Connections I tried, all with the same color contrast ghosting issue (and to restate, it worked fine on an Intel HD5500, but bad on this UHD620):

 

Direct: Laptop HDMI out => Samsung HDMI in

Official Dock: Laptop USB-C out => Thinkpad Dock DisplayPort out => Converter Cable to HDMI out => Samsung HDMI in.

Cheap Dock: Laptop USB-C out => Cheap Dock HDMI out => Samsung HDMI in.

 

Alas, the Monitors do not had DisplayPort in, so I cannot try that directly.

 

Maria_R_Intel
Moderator
364 Views

Hello Maurits,


I would like to do more research about this, I will post back on this thread as soon as possible.


 

Best regards,

Maria R.

Intel Customer Support Technician


Maria_R_Intel
Moderator
322 Views

Hello Maurits,


Thank you for patiently waiting.


It appears that there might be a compatibility issue between the laptop and the Samsung TV used because other monitors like the Acer '27 doesn’t have the issue.


The best course of action will be to check this with the laptop manufacturer for any BIOS update hoping that it can also update the VideoBIOS to include improved compatibility.


Intel cannot guarantee that the components we provide are going to be compatible with 100% of all devices available in the market.



Please contact Lenovo* to verify the updates and check the compatibility.


Best regards,

Maria R.

Intel Customer Support Technician


Maurits
Beginner
284 Views

Just to supplement this thread:

Based on above, and reading up on DP and DP++, I realized I (probably) only had " passive"  DP++ to HDMI converters, 1080p to boot. So regardless of my cable, conversion would always be offloaded to the suggested LSPcon chip.

So I invested in an top end *active* 4K 60Hz capable DP to HDPI converter. Just so the conversion would be done by a different chip.

But alas, same. So active adapter also does not help. Not that anyone suggested it, but I though to suplement this thread anyway.

Reply