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Missing refresh rate options on display connected to Thunderbolt hub to Iris XE graphics

GabrielTVG
Beginner
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Hi! I have this setup:
-Nitro 5 AN517-55 Laptop with Intel 12700H and Iris XE Graphics and HP Elitebook G10 with Intel 1345U processor and Iris XE Graphics, both running Windows11 Pro 23H2 
-Dell WD22TB4 Thunderbolt 4 Hub
-Dell Alienware AW2723DF 240HZ ( and up to 280 HZ support ) monitor connected through DP-Type C cable to the Hub

The hub does support the 280HZ of the display and the option does show in windows when selecting the refresh rate option.
The problem is that when i unplug the hub and connect it back again, i get the options limited to 144HZ until I restart any of the laptop I do this to, then the 280HZ option comes back. If i try to use the display with HDMI or DP, i get only up to 240HZ however the option always remain, not mattering how many times I plug/unplug the hub while any laptop is on.

Any ideas how can this be fixed or can be done about it? The hub is up to date with the drivers. I don't use the DP-DP or HDMI cables because I lose the 10 bit color and is 8 bit with dithering + the 40 HZ ( not that much of a problem that ) . If I need to post anything else or is posted in the wrong area, sorry about that, just let me know what needs to be done and will try to fix it.

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MUC
Valued Contributor III
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Summary of your devices:

 

Acer Nitro 5 AN517-55

1 x Thunderbolt 4

1 x HDMI 2.1 FRL

HP EliteBook 840 QuickSpecs

2 x Thunderbolt 4

1 x HDMI 2.0 TMDS

 

Dell Alienware AW2723DF

2 x HDMI 2.0 (2560 x 1440 @ 144 Hz)

1 x DisplayPort 1.4 (2560 x 1440 @ 240 Hz; @ 280 Hz overclocked)

 

Dell Thunderbolt Dock WD22TB4

 

MUC_0-1730148362382.png

 

Calculating bandwidth requirements based on information in the monitor's user manual:

 

MUC_2-1730150829109.png

 

If you only have 144 Hz available, then you are also limited to 8-bit color depth (BPC). Is that correct?

If so, the negotiation of the connection speed apparently results in only DisplayPort HBR2 protocol being available.

 

Please describe in more detail what you are connecting where with which cable. It is not clear to me yet.

 

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GabrielTVG
Beginner
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The Dell Alienware AW2723DF monitor is connected through one DP-Type C cable on one of the Thunderbolt ports marked as 7 in the diagram of the hub. The whole hub is connected through the cable of the Hub marked as HOST to the thunderbolt ports of any of the 2 given laptops, the one on the back of the Nitro 5 or the port marked as 11 on the HP . With this DP-Type C cable, the 1440P 280 HZ 10 bit setup is possible however, if I disconnect the hub while the laptop is on ( even in stand by with the lid closed ), I lose any other option above 144Hz and I need to restart it to get all the options back. If I use the DP-DP cable on any of the ports marked as 1, I am limited to 240HZ 8 bit with dithering, as it is a limitation of the hub itself, but the option is always there whatever I do with it (connect it while laptop is on/off, lid closed/open, etc). The 10 bit and HDR options are still available and active whatever I do, just the refresh rate options are gone.

Display without 280hz option.png

Those are the options I get in the situation described initially, where anything above 144Hz is missing but the 10 bit and HDR are still on.

Display with 280Hhz option.png

 Those are the options I get if I restart the laptop the hub is connected to, 10 bit and HDR still being on. ( 

HZ checker.png

Tested on ufo test website, the option of 280 Hz actually works and it does what it says, it is just that it disappears if the hub gets disconnected. I tested to be sure it isn't the hub itself, as even if restarting it completely, reattaching the cable of the display or anything I do with it, same thing happens, the options appear only if the whole laptop is restarted ( or maybe some process restarted, restarting explorer.exe at least doesn't change anything ).
Edited: added links to DP-Type c cable in case it has any relevance and to the refresh rate tester site.

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MUC
Valued Contributor III
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In my opinion, the cable is good and this connection method is the right one.

 

I would like to check the video timing, so could you please create reports for both cases shown above and attach the two output files here?

 

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GabrielTVG
Beginner
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Here are the 2 files, one with the 280 Hz option avalaible and the second one with the added - missing Hz after the hub was unplugged and plugged back in. The Intel Graphic Command Center app was fully restarted between the generating of the files.

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MUC
Valued Contributor III
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Unfortunately, the data is not entirely conclusive. Please run edid-dump.exe if you have 280 Hz available:

 

https://www.monitortests.com/edid-dump.zip

 

This will create a file named "edid-dump.txt" in the same folder. Please attach this TXT file here.

 

Don't worry. This data is just encoded data of the information sent from the monitor or dock to the laptop: This is called Extended Display Identification Data (EDID). No personal data or other system information is read through it.

 

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GabrielTVG
Beginner
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Here is the generated edid-dump file. I looked a bit over what 2 sites translated the information to but I didn't manage to come to a conclusion, so I will wait to see what you understood from that data. Generated 2 files, one with the missing options and one when the 280 HZ option is available but it generated 2 identical files.

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MUC
Valued Contributor III
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Yes, that looks better. The relevant part is the one below "DISPLAY\DELA208\4&150948E&0&UID20550".

You can copy this section to the clipboard and paste it here to decode it. Please paste in the left black box and hit "Process" button below. You'll see the result in the right black window.

I'll come back as soon as I can.

 

 

00 ff ff ff ff ff ff 00 10 ac 08 a2 4c 36 39 30
28 21 01 04 b5 3c 22 78 3b 97 e0 ac 50 46 a9 24
0e 50 54 a5 4b 00 71 4f 81 80 a9 c0 d1 c0 01 01
01 01 01 01 01 01 56 5e 00 a0 a0 a0 29 50 30 20
35 00 55 50 21 00 00 1a 00 00 00 ff 00 37 46 32
4d 4e 50 33 0a 20 20 20 20 20 00 00 00 fc 00 44
45 4c 4c 20 41 57 32 37 32 33 44 46 00 00 00 fd
0e 30 19 a0 a0 71 01 0a 20 20 20 20 20 20 02 cf

02 03 27 f1 4c 3f 22 21 20 1f 13 12 10 04 03 02
01 23 09 07 07 83 01 00 00 e3 05 c3 01 e6 06 05
01 76 76 1f e2 00 ea 40 e7 00 6a a0 a0 67 50 08
20 98 04 55 50 21 00 00 1a 6f c2 00 a0 a0 a0 55
50 30 20 35 00 55 50 21 00 00 1a a0 dd 80 78 70
38 50 40 1c 20 98 0c 55 50 21 00 00 1a 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 b0

70 12 79 03 00 03 01 28 ca 9c 01 08 ff 09 9f 00
2f 80 1f 00 9f 05 b2 00 02 00 04 00 3b b8 01 08
ff 09 9f 00 2f 80 1f 00 9f 05 27 00 02 00 04 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 c4 90

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MUC
Valued Contributor III
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So what always works:
2560 x 1440 @ 144 Hz RGB 10-bit HDR

 

With the video timing that can be seen from the EDID, we arrive at a pixel clock of 592 MHz, a bandwidth requirement that is higher than the HBR2 protocol. This means that the HBR3 protocol runs in any case. So that is probably not the problem.

 

If we take a closer look at the EDID read in via the DisplayPort Auxiliary channel (pin 15/17):

 

MUC_0-1730397060547.png

 

EDID is sent from the display to the graphics card and is structured in 128 byte blocks. It's supposed to tell the graphics driver what the display (or the dock) offers as capabilities. The moment the HOST cable is plugged into the laptop, HPD (Hot Plug Detect, Pin 18) becomes TRUE and the graphics driver must then read the EDID from the DP AUX CH.

 

But this seems to be going wrong here, as the driver only processes the first two blocks. This means that you have a maximum of 144 Hz available because this capability is still in block 1. Block 2, which defines everything above that, is apparently missing.

 

We can test what happens if you have the laptop in the state where 280 Hz is missing and then you don't restart the whole device, but just restart the Windows graphics card driver. If the driver then reads the EDID again and everything is there, then we have a driver error related to HPD.

Please test as follows:

  1. Download Custom Resolution Utility (CRU). The download ZIP contains some files.
  2. Restore the laptop to the state where 280 Hz is missing.
  3. Then run "restart64.exe". The Windows graphics driver will be reloaded as if the system were restarting.

 

Is 280 Hz now available again?

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GabrielTVG
Beginner
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Tried restarting with restart64.exe as you said. The option did not appear back unfortunately, still the same ones from the first replies. However the screen with the missing refresh rates does this weird green flickering, this is what i managed to capture as it does it very fast. Don't know if is normal or no, just wanted to point it out in case it is not normal, if it is, ignore then. Any other ideas what to try or might the problem be or how to fix? Even if it is something "temporary" like this restart thingy if it would have worked.20241101_124457.jpg

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MUC
Valued Contributor III
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I suspect that the graphics driver is not handling the EDID correctly. Possibly because it is not receiving it properly. I assume you have already tried the obvious things:

 

Firmware Update of the monitor and installation of the Dell drivers

Firmware Update of the Dell Thunderbolt Dock

 

If that doesn't help, we can still try to write the desired EDID into the Windows registry using CRU. To do so, please proceed as follows:

 

  1. Download the TXT file from the attachment. It contains the EDID as shown in the images above.
  2. Run "CRU.exe" from the CRU download package.
  3. After the monitor is selected at the top, click on "Import" at the bottom left:

    MUC_0-1730494191349.png

     



  4. Close CRU with OK and restart the computer.

 

This process can be reversed at any time: In this case, run “reset-all.exe” from the CRU download package and restart the computer.

 

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GabrielTVG
Beginner
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Tried everything that you mentioned. As that old movie title, "The good, the bad and the Ugly", here is what happened:
The good: good thing you mentioned the drivers. The monitor one wasn't updated and it was an older one, now it is up to date to what is on website. 

Monitor firmware.png (ss from the monitor firmware update utility)

Also tried the CRU app with the modified EDID. Now the monitor does launch with 280HZ preselected when starting the laptop ( but wait for the ugly.... )

The bad: the hub drivers were already up to date, as it was one of the first things i tried after i noticed the problem and also the graphic drivers for the intel iris xe are the latest one for this laptop.

dock.png (ss from the dell dock package updater)

driver video.png (ss from intel driver assistant)


The ugly: the problem still persists. When disconnecting the hub and reconnecting it, the refresh rate options are missing above 144 ( as the original problem ) and still defaults to 144HZ as it is the highest one, until a pc restart ( not even the restart64 works, needs full pc restart ), then it defaults to 280Hz.

 

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MUC
Valued Contributor III
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I noticed something else when calculating the necessary link speed for the refresh rates and bit depth in question: Display Stream Compression (DSC) is required for 240 Hz and higher. This is also stated in the monitor's manual:

 

MUC_0-1730505375791.png

 

You definitely have DSC activated in your monitor, otherwise the high refresh rates would never work.

You can check in the monitor's OSD:

 

MUC_1-1730507273684.png

 

My current assessment is therefore:

  • Link Rate = HBR3 = OK
  • EDID = probably OK

Since the EDID may have changed with the monitor update and we forced the "old" EDID onto the Windows operating system via CRU, please do the following:

  • Run "reset-all.exe" from the CRU download package and restart. When the system starts up, the original EDID from the DP AUX CH and the monitor driver is automatically used again.
  • If 280 Hz is then available, please run "edid-dump.exe" again so that we can check whether the monitor update has changed the original EDID of the monitor. Please attach the new "edid-dump.txt".

 

Please also check whether the problem also occurs if you connect the laptop directly to the monitor and then disconnect and reconnect it.

 

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GabrielTVG
Beginner
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Yes, DSC is enabled. I reseted the EDID and restarted the whole laptop, 280HZ option is still there and the initial problem still happens with the display connected through the hub.
I also connected the display directly as you mentioned directly in the laptop, the 280Hz option is available and the problem does not occur, if I unplug the display from the laptop and plug it back, the 280Hz option is still there and selected by default (after I selected it, as it defaulted to 60Hz initially on the first plug in). So I guess the problem might be actually from the hub itself somewhere?
I compared the original EDID dump with the one you requested now and another one only with the display connected directly, they are the same except the fact the letters are capital instead of the small ones and the identifier of the screen is different when connected directly to the laptop, I attached the 2 in the response so you can look yourself.

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MUC
Valued Contributor III
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Yes, I can confirm that the EDID is the same in each case. Upper or lower case characters don't matter.

 

The bottom line now is that if you only have 144 Hz to choose from, the graphics driver doesn't recognize that it can also use DSC. Otherwise it would offer 280 Hz to choose from. I can at least replicate this dependency in my simulation here with my NUC11 and Iris Xe.

Since I'm not a driver programmer, we unfortunately can't see into the internal processes. I wouldn't necessarily blame the dock either. As you can see from our analysis, the process of establishing video connections is always a give and take. Unfortunately, without professional analysis by Intel/Dell, this cannot be narrowed down any further.

At the moment you've done everything right. In my opinion, you can also leave out the CRU trick. You can of course send a request to Dell with reference to this thread. We'd have to wait and see whether anything comes of it.

 

@Intel Customer Support Technicians: Do you have the ability to investigate this issue in your labs?

 

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GabrielTVG
Beginner
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Fair enough. Do you have by any chance a link where I could write/send a form or something like that to Dell to what you mentioned so I can ask them as well what the issue could be and if it can and how it can be fixed, while referencing this thread? Also, thank you very much for the help and the involvement, really gave some cool insights and good help! 😁

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MUC
Valued Contributor III
3,178 Views

@Intel Customer Support Technicians:

 

Issue short description:

Hot Plug to Dell Thunderbolt Dock WD22TB4 does not recognize the need for DSC.

 

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Mike_Intel
Moderator
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Hello GabrielTVG,


Thank you for posting in Intel community Forum.


Upon reviewing the Dell Thunderbolt Dock WD22TB4 manual. According to the manual (page 7), the maximum refresh rate for this dock is 60Hz. For issues like this, it is advisable to check with Dell to ensure the setup is fully compatible.

 

Although Windows may show an option to select a higher refresh rate using the monitor's overclocking feature (page 45), each OEM can customize their setup. Therefore, it is best to confirm this with Dell.


If you have questions, please let us know. Thank you.


Best regards,

Michael L.

Intel Customer Support Technician


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GabrielTVG
Beginner
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Hi! I did look around and tried to get informations about this. The final conclusion we ( me and other users of this hub and even older models like the WD19TB, which is the same Hub as the 22 but the Thunderbolt module upgraded to 2 Thunderbolt 4 ports instead of one Thunderbolt 3 ) got to is that the dock does support more than 60HZ but the manual shows only for that value as is the most common one used for office work or in general. The Thunderbolt 4 port supports video transfer to whatever you give it and has the speed necesarry to process it ( the 40gb/s limit of the Thunderbolt 4 port speed and the DP 1.4 of the display ). As the 1440P 280HZ 10 bit runs with DSC, it shows and works perfectly fine, the only problem being the one described in the topic, and that is the missing refresh rates if I plug the hub with the laptop on/stand by mode.
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Mike_Intel
Moderator
2,721 Views

Hello GabrielTVG,


Thank you for the update.


That is why we recommend also to check this with Dell if they have recommendations or workaround since they know the capabilities of the hardware that they may have altered/modified.


If you have questions, please let us know. Thank you.


Best regards,

Michael L.

Intel Customer Support Technician


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