Intel HD Graphics 530: 3840x2160@60Hz on HDMI 2.0 is not chroma 4:4:4 but only 4:2:0

[DJoli]

Issue: As soon as the Intel HD Graphics driver is "Enabled", HDMI 2.0 UHD 3840x2160@60Hz chroma automatically degrades to 4:2:0 !

(When the Intel HD Graphics driver is "Disabled", HDMI 2.0 UHD 3840x2160@60Hz chroma come back to 4:4:4, but with a few more %CPU used)

Motherboard: Gigabyte Z170X-UD5 TH (BIOS: F4)

CPU: Intel i7-6700K

RAM: 2x8Go G.Skill Trident Z 3200 Mhz

HDD: Samsung 950 Pro 256Go NVMe

GPU: Integrated HD530 of the i7-6700K (HDMI 2.0 output via MegaChips MCDP2800)

OS: Windows 10 Home 64 bits (fresh USB install. No other software installed)

Intel HD Graphics Driver: 10.18.15.4279

Monitor: iiyama X4071UHSU-B1 (HDMI 2.0)

HDMI cable: High Speed HDMI cable supplied with the monitor.

How to repro:

- Install fresh Windows 10 64 bits OS.

- Set display to UHD 3840x2160@60Hz. ---> Chroma is OK 4:4:4.

- Install Intel HD Graphics Driver ---> Chroma is automatically 4:2:0 when 3840x2160@60Hz (it's 4:4:4 when 3840x2160@30Hz) !

The technical specifications of the motherboard and the monitor indicates they both can do 3840x2160@60Hz chroma 4:4:4 with 8 bits per color via HDMI 2.0.

Why does it fail when Intel HD Graphics Driver is Enabled ?

[idata]

Hello @David_fr,

I noticed that the driver you have installed is an older version, let's try updating it. This is the latest version available from our end; https://downloadcenter.intel.com/download/26228/Intel-Graphics-Driver-for-Windows-10-and-Windows-7-8-1-15-40-?product=88345 Download Intel® Graphics Driver for Windows® 10 and Windows 7*/8.1* [15.40], use this method for the installation http://www.intel.com/content/www/us/en/support/graphics-drivers/000005629.html How to Manually Install an Intel® Graphics Driver in Windows® 10 &.... You will also find Beta version https://downloadcenter.intel.com/download/26305/Intel-Beta-Graphics-Driver-for-Windows-10-and-Windows-7-8-1-15-40-?product=88345 https://downloadcenter.intel.com/download/26305/Intel-Beta-Graphics-Driver-for-Windows-10-and-Windows-7-8-1-15-40-?produ…, which I also recommend trying it.

Regards,

Amy.

[DJoli]

Hi,

Thank you for your suggestions but it is worse now ! Immediately after installing the Intel graphic driver, the HDMI output is disabled ! The screen immediately becomes black and displays it's "No signal" message. Then the monitor enters in sleep mode...

The motherboard BIOS is now version "F5" (latest).

I tried on a fresh new installation of Windows 10 v1607 (OS version 14393.0).

I also tried on an updated Windows 10 v1607 (OS version 14393.222).

I tried both Intel Graphics Driver : v20.19.15.4501 and v20.19.15.4530 (beta), each on a fresh new installed Windows 10 each time :

The results were always the same: Black screen with "No signal" error message !

(Note: All is OK when I use the thunderbolt3 USB-C to Display-Port câble, instead of the HDMI 2.0)

[idata]

Have you tried using a different HDMI cable?

Regards,

Amy.

[DJoli]

This HDMI câble works very well with 3840x2160@60Hz... until the Intel Graphics Driver is installed !

[idata]

I understand, but in this case I would recommend testing a different HDMI cable, and this is because normally the cables provided with monitors are standard quality. Testing a different cable will help to narrow the issue.

Regards,

Amy.

[DJoli]

I tried with another HDMI cable. Same results ! Black blank screen...

But, I tried Something else:

I connected the monitor using my Thunderbolt3 to DisplayPort cable to be able to open the display's parameters window and have the input focus inside the list of display frequencies. Then I unplugged the displayPort cable and I plugged the HDMI cable. The monitor became black and entered in sleep mode. I was "blind"... But, my input focus was still in the "Select frequency" list-box. So I managed to select the 30 Hz frequency... Then the monitor awaked and I got the Windows's desktop on screen ! Thus, HDMI works fine in 3840x2160@30Hz mode !

(So, I think that, after a clean install, the Intel Graphics Driver automatically choose 3840x2160@60Hz mode (as this is the monitor's prefered mode) but 60Hz frequency don't work ! Before (when I opened this thread), 3840x2160@60Hz worked well but was chroma 4:2:0... May be now the Intel Graphics Driver is trying to do 3840x2160@60Hz with chroma 4:4:4 ???

Note:

I have noticed a strange thing: In the Intel HD Graphics Control Panel, when creating a Display Custom Resolution, the vertical's total seam to be erroneous (3+54+5+2160 = 2222, not 2273 !?). Could this be in relation with the issue ?

English version of this window:

Many thanks for your help.

David

[idata]

David, thank you for trying the HDMI cable.

"So, I think that, after a clean install, the Intel Graphics Driver automatically choose 3840x2160@60Hz mode"

This is correct and it's expected, once you have our driver installed it will pick the native resolution from your TV, which according to this link http://www.iiyama.com/gl_en/products/prolite-x4071uhsu-b1/ http://www.iiyama.com/gl_en/products/prolite-x4071uhsu-b1/, 3840 x 2160 is the native. So, based on this I suspect that there is an issue with our driver and your system configuration; therefore, I would like you to try with the driver provided by your computer manufacturer. See here for it http://www.gigabyte.com/products/product-page.aspx?pid=5479# dl GIGABYTE - Motherboard - Socket 1151 - GA-Z170X-UD5 TH (rev. 1.0).

Let me know it goes.

Regards,

Amy.

[DJoli]

OK. I tried the driver provided by the the manufacturer of my motherboard. Result : It's a return to the first post of this thread : HDMI 3840x2160@60Hz "works" but is automatically at chroma 4:2:0 ! It's impossible to get chroma 4:4:4 😞

Symptoms are exactly the same as in my first post on this thread, but :

Bios is now version F5

I installed a clean new Windows 10 v1607 (OS version 14393.0).

I installed the latest manufacturer's graphic driver (it is Intel Graphic Driver 20.19.15.4364)

What about the wrong calculation of the vertical settings' total in Intel HD Graphics Control Panel when defining a custom resolution ? Could the same erroneous value be calculated elsewhere too and cause the chroma issue ? (This wrong calculation also distorts the calculated Pixel Clock Frequency (called "Fréquence d'horloge des pixels" in the french screenshot) which then exceeds the max pixel clock permitted by the Iiyama display (533.25 Mhz). Could this be the reason why the Intel Graphics driver wrongly chooses to reduce chroma to 4:2:0 or transmits bad video timings so that the display becomes blank black ?)

Link to a http://www.epanorama.net/faq/vga2rgb/calc.html Video timing calculator

Many thanks for your help.

[idata]

Thank you for the information.

Please let me review your thread, as soon as I have more information I will update the thread.

Regards,

Amy.

[DJoli]

Thanks.

Here are more details about the Intel driver's calculation bug :

I wonder if this error of calculation could also be done elsewhere in the Intel Graphics driver and that causes the display issues...

Many thanks,

David

[idata]

Thank you for your patience.

I confirmed with our engineering team that 3840x2160@60hz 8 bits per color with 4:4:4 is possible on Skylake in default mode. HDMI 2.0 specification cannot support 4:4:4 with 3840x2160@60Hz @10/12bits per color.

According to the monitor's datasheet, your display is 10-bit. Here you can find the data sheet; http://iiyama.com/gl_en/products/prolite-x4071uhsu-b1/466,prolite-x4071uhsu-b1.pdf http://iiyama.com/gl_en/products/prolite-x4071uhsu-b1/466,prolite-x4071uhsu-b1.pdf. With that fact on the table the following can be done;

• 4:2:0 output will happen if it is a HDMI 2.0 display and the system has HDMI 2.0 10-bit or 12-bit output, and this appears to be the case here.
• 4:2:0 output will also happen if doing UHD HDR video playback.

One more thing, if your monitor keeps pushing for 10-bit display (even if Windows is configured for 8-bit) then the switch from 4:4:4 to 4:2:0 is expected behavior based on the GPU's limitation.

Regards,

Amy.

[DJoli]

Hi Amy,

Thank you for your investigations but, in the Gigabyte Z170X-UD5-TH motherboard, the Skylake's HDMI output is not used. This motherboard only uses Skylake's Displayport outputs and converts it to HDMI using an on-board MegaChips MCDP2800 converter. According to the http://www.megachips.us/products/documents/MCDP28x0_Databrief.pdf MegaChips' datasheet, this MCDP2800 is able to handle 4:4:4 on 3840x2160@60Hz, 8 bits per pixel, on HDMI 2.0. If the Intel's Custom Resolution panel was working well, it should be possible to define a 8 bits color depth UHD custom resolution (instead of 10 bits pushed by the monitor)... So, what about the Intel HD Graphics Control Panel's custom resolution's vertical total's bug ?

[idata]

Thank you for that information.

As mentioned before from our end, it's considered expected behavior based on the GPU's limitation; however let me double check that.

Regards,

Amy.

[idata]

@David_fr, I am still checking on this.

There might be a driver that can help here, that driver is 4463; https://downloadcenter.intel.com/download/26078/Intel-Graphics-Driver-for-Windows-10-and-Windows-7-8-1-15-40-?product=88345, so please give it a try and let me know how it goes.

Regards,

Amy.

[DJoli]

Hi Amy,

As you suggested, I tried Intel HD graphics driver 4463 (on a fresh clean install of Windows 10 v1607, OS v14393.0). The result is exactly the same as with Intel driver 4501 or 4530 (that is, same as in post # 2 of this thread) :

a) As soon as Intel Graphic driver is installed, I get a black blank screen on HDMI monitor. When I managed to set 30Hz refresh rate, then it's OK on HDMI.

b) In the Intel HD Graphics custom resolution's advanced panel, the calculations of vertical timings is still erroneous, so the calculated pixel-clock is false too.

c) I noticed that when my monitor is connected to my PC's motherboard using a Thunderbolt3 USB-C to Displayport cable, then the monitor is seen by the Intel HD Graphics driver as a Displayport connected "Digital Display". But when my monitor is connected to my PC's motherboard using a HDMI cable, via MegaChips MCDP2800, then the monitor is seen by the Intel HD Graphics driver as a Displayport connected "Digital Television"... Where does this difference come from ?

What solution could you propose to allow me to use my hardware to its optimal possibilities, that is 3840x2160@60Hz, chroma 4:4:4, 8 bits color's depth, on HDMI 2.0 (internal Displayport's output converted to HDMI by MCDP2800) ?

Will you correct the Custom resolution's vertical timings calculation bug ?

Many thanks,

Regards

David

[idata]

David, thank for sharing your results.

We are still investigating your case, your results will definitely help with the research. As soon as I have more answers for you, I will update the thread.

Regards,

Amy.

[RonaldM_Intel]

Hello David,

We released a new Baseline of drivers, meaning that is brand new code, specifically designed for 6th and 7th generation graphics controllers. Please install this driver and let us know if you still see the 4:2:0 degradation.

https://downloadcenter.intel.com/download/26404/Intel-Graphics-Driver-15-45- Download Intel® Graphics Driver [15.45]

I would also appreciate if you can test the vertical timings calculations while using this driver.

I'm sorry for asking you to test with so many different drivers, but we want to get to the bottom of this issue and your feedback is extremely helpful to us.

We're also checking why the HDMI connection is detected as "Digital Television". This could very well be the inner workings of the signal conversion done by the LSP-Con chip, but I'll confirm this and let you know as soon as I can.

Regards,

[DJoli]

Hello Ronald,

I installed your new (above given link) Intel Graphics Driver [15.45] on a new clean install of Windows 10 v1607 (OS v14393.0).

My monitor was allways connected HDMI during all the Microsoft's OS and Intel's driver installations. I had no network connection (no Internet, to be sure that nothing come automatically from Windows Update).

I got exactly the same results as with other drivers : Black blank screen as soon as the Intel HD Graphics driver is installed !

(I took many screen shots during this installation, even when the monitor became blank (so I could see that Intel HD Graphics Driver automatically choosed 59Hz for my monitor (when connected using HDMI cable via LSP-Con as well as when connected using Displayport cable via Thunderbold3).

Here are some screenshot I took during and after Intel HD Graphics Driver installation (I'm sorry, all theses screenshots are in French because I could'nt add another language without an access to the Internet) :

At the beginning, there's only the Windows10's default graphic driver (1024x768 desktop's resolution), I execute the Intel's driver setup.exe file:

I took this screenshot immediately after the monitor became blank during driver installation. This is half a second after my monitor became blank (so It was not viewable on screen):

A closer look:

After the driver's installation completed, I manually selected 60Hz (instead of 59Hz) when using Displayport cable and it works fine (so why the Intel's driver choosed 59Hz ?). I manually managed to select 30Hz when using HDMI cable (despite the monitor was blank) so that the monitor "awaked" and now became usable in HDMI.

Bad news, the Intel's Custom Resolution is still erroneous (calculated vertical total is bad, exactly same errors than in my post # 10 of this thread) and this calculation errors are exactly the same when monitor is connected using HDMI or Displayport :

It may be usefull for your engineers team to have a look at the Intel's driver information reports (RAW EDID ?) when the monitor is connected via Displayport (all is OK) and via HDMI 2.0 (no picture above 30Hz refresh rate) :

Intel's driver information report (when monitor is connected via Displayport) :

Intel(R) HD Graphics 530

Report Date: Sunday, November 27, 2016Report Time [hh:mm:ss]: 1:30:59 PMDriver Version: 21.20.16.4542Operating System: Windows* 10 Home (10.0.14393)Physical Memory: 15807 MBVendor ID: 8086Device ID: 1912Device Revision: 06Graphics Output Protocol (GOP) Version: 9.0.1042Current Resolution: 3840 x 2160Processor: Intel(R) Core(TM) i7-6700K CPU @ 4.00GHzProcessor Speed: 4008 MHzProcessor Graphics in Use: Intel(R) HD Graphics 530Shader Version: 5.1OpenCL* Version: 2.0* Microsoft DirectX* *Runtime Version: 12.0Hardware-Supported Version: 12.0* Devices connected to the Graphics Accelerator *Active Displays: 1* Digital Display *Display Type: DigitalDDC2 Protocol: SupportedGamma: 2.2Connector Type: DisplayPortDevice Type: DisplayPortMaximum Image SizeHorizontal Size: 34.65 inchesVertical Size: 19.29 inchesSupported Modes640 x 480 (60p Hz)640 x 480 (67p Hz)640 x 480 (72p Hz)640 x 480 (75p Hz)720 x 400 (70p Hz)720 x 480 (60i Hz)720 x 480 (60p Hz)720 x 576 (50i Hz)720 x 576 (50p Hz)800 x 600 (72p Hz)800 x 600 (60p Hz)800 x 600 (56p Hz)800 x 600 (75p Hz)<span s...

[DJoli]

Hello Ronald,

Did you find a fix to all these issues ?

1) Incorrect 4K UHD output, making the HDMI monitor to become blank as soon as the iIntel's driver is installed.

2) Incorrect vertical timings calculations in the Intel's custom resolution panel.

3) 59Hz scan rate choosed automatically despite the 60Hz monitor's preferred scan rate.

Do you have a solution to make my hardware to work as it should do ? 3840 x 2160 @60Hz, 8 bits colors depth, full 4:4:4 chroma (no subsampling) when monitor is connected to the MCDP2800's HDMI 2.0 output ?

Regards

David

[RonaldM_Intel]

Hello David,

I apologize, I was caught up in the new Beta release for Skyrim* and with other issues reported by the community. I do have your case in our queue.

Just one clarification: Upon further reading, I am under the impression that if you set 3840x2160@60hz you get no video, is that the case or am I mistaken?

Regards,