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Summary of your devices:
1 x Thunderbolt 4
1 x HDMI 2.1 FRL
2 x Thunderbolt 4
1 x HDMI 2.0 TMDS
2 x HDMI 2.0 (2560 x 1440 @ 144 Hz)
1 x DisplayPort 1.4 (2560 x 1440 @ 240 Hz; @ 280 Hz overclocked)
Calculating bandwidth requirements based on information in the monitor's user manual:
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.
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.
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.
Those are the options I get if I restart the laptop the hub is connected to, 10 bit and HDR still being on. (
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.
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):
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:
- Download Custom Resolution Utility (CRU). The download ZIP contains some files.
- Restore the laptop to the state where 280 Hz is missing.
- Then run "restart64.exe". The Windows graphics driver will be reloaded as if the system were restarting.
Is 280 Hz now available again?
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.
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:
- Download the TXT file from the attachment. It contains the EDID as shown in the images above.
- Run "CRU.exe" from the CRU download package.
- After the monitor is selected at the top, click on "Import" at the bottom left:
- 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.
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.
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.
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.
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:
You definitely have DSC activated in your monitor, otherwise the high refresh rates would never work.
You can check in the monitor's OSD:
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.
