Intel HD4600 Color Dithering Issues on Non-OEM Images

[ZMilb]

Good afternoon;

On our new machines using the Intel HD4600, we have encountered issues with color-dithering issues on Windows 8.1 Enterprise and the Windows 10 Technical Preview. I am going to engage Lenovo technical support on this, but as the problem has been narrowed down to the HD4600 graphics, I thought I would try here as well:

• The issue is not present on Windows 7 Enterprise corporate image
• The issue is not present on OEM Windows 8.1 Pro image
• The issue is present on Windows 8.1 Enterprise install (even with a vanilla Microsoft ISO installation)
• The issue is present on Windows 10 Enterprise Technical Preview (even with a vanilla Microsoft ISO installation)
• The issue is not resolved by updating/downgrading graphics drivers - revisions from 2013 to 2015 have been attempted
  • OEM drivers from the 100% functional OEM image were captured, but when redeployed on a corporate Win 8.1 Enterprise image, does not correct the issue
• The issue is resolved when using non-Intel, non-accelerated "Microsoft Basic Display Driver"
• The issue is not able to be captured with screenshots - screenshots will display normally on a non-affected systems

The issue is mostly prevalently seen on images/wallpapers with solid color variance, the "Metro UI" styled Windows 8.1 Start Screen icons of solid colors, and various graphical dialog boxes.

Screenshots from a physical camera pointed at the LCD - Captured screenshots will not reflect the issue in the image file:

Similar issues from users on this forum:

/message/198199# 198199 https://communities.intel.com/message/198199

I've expired my troubleshooting skills for this one - generally things like this are driver-related, but I've disproved that.

Any ideas? Obscure registry entry perhaps?

Any help would be much appreciated; thank you for your time and support.

[ROBERT_U_Intel]

Could you provide a bit more information on your system?

What is the display model?

What resolution and refresh rate is the display running at?

What is the latest driver version number you have tried?

Can you post a DXDiag report of a system with the issue to this thread?

Thanks

Robert

[ZMilb]

I'm not near my test unit right now, so I will have to get back to you on some of those details. I did pull a dxdiag before I left - I am attaching it to this post. Be aware this is on the Windows 10 preview, as I was seeing in Win 10 behaved differently from 8.1 - I can reimage with 8.1 Enterprise and provide that instead if you want info from a production OS. I believe some of the info you requested, such as Intel HD4600 driver version, should be included in the info dump.

The models current exhibiting this behavior are the Lenovo ThinkPad W540 and W541 (very similar hardware), on the internal LCD. Unlike previous models, (correct me if I'm wrong here, Intel Engineers) the discrete GPU combo on these rely heavily on the Intel chipset/Intel HD4600 for final screen rendering.

As far as I can tell the non-Intel GPU cannot act independently, and is completely reliant on the HD4600 for the final steps of the video output. This seems like a different method than was used on previous combo GPU's on the W520/W530 where the graphics processing seemed less intertwined. I'm also engaging Lenovo with this, as obviously it works OK in their off-the-disc OEM image.

Let me know if you also would like additional visual aids as to the problem being seen, as I know it's obscure to describe.

[ROBERT_U_Intel]

Thanks for the additional info. Would it be possible to post the above original image (flower) to this thread? It is a perfect source for exposing this issue.

Thanks

Robert

[ZMilb]

Robert,

Thanks for your continued support.

Here is the original image in question:

[ROBERT_U_Intel]

Hi

We have tested this issue on several system including an NVidia GTX Titan system and we see the same issue on all system with and without the drivers installed. We also used Device Manager and disabled the Intel Graphics and there was no change in the appearance of the image. We also saw the same results on Win 10TP, Win 7, and Win 8.1. So basically we are at a loss as to why your results are different.

Question, do you see the issue when an external display is connected to the laptop?

Thanks

Robert

[ZMilb]

Robert,

I can only replicate the issue on the ThinkPad W540 and W541. Other systems with the HD4600 are not affected. I am working with Lenovo, since it is specific to these two models.

Lenovo also had me try the external LCD - it works ok with the external display. Although this issue seems specific to Lenovo models, I will let you know in this thread if I receive a solution via Lenovo support.

Thanks for your time and efforts.

[ROBERT_U_Intel]

What color depth is the LFP running at?

[ZMilb]

The display is running at 32 bit color depth - unchangeable to anything else

Is that the info you were asking about?