I previously blogged about buying a refurbished Hisense 65u80g 8K TV with the aim of making it a large monitor [1] and about searching for a suitable video card for 8k [2]. After writing the second post I bought an Intel Arc B580 which also did a maximum of 4096*2160 resolution.
This post covers many attempts to try and get the TV to work correctly and it doesn’t have good answers. The best answer might be to not buy Hisense devices but I still lack data.
Table of Contents
Attempts to Force 8K
I posted on Lemmy again about this [3] and got a single response, which is OK as it was a good response. They didn’t give me the answer on a silver platter but pointed me in the right direction of EDID [4].
I installed the Debian packages read-edid, wxedid, and edid-decode.
The command “get-edid > out.edid” saves the binary form of the edid to a file. The command “wxedid out.edid” allows graphical analysis of the EDID data. The command “edid-decode out.edid” dumps a plain text representation of the output, the command “edid-decode out.edid|grep VIC|cut -d: -f2|sort -n” shows an ordered list of video modes, in my case the highest resolution is 4096×2160 which is the highest that Linux had allowed me to set with two different video cards and a selection of different cables (both HDMI and DisplayPort).
xrandr --newmode 7680x4320 1042.63 7680 7984 7760 7824 4320 4353 4323 4328 xrandr --addmode HDMI-3 7680x4320 xrandr --output HDMI-3 --mode 7680x4320
I ran the above commands and got the below error:
xrandr: Configure crtc 0 failed
At this time I don’t know how much of this is due to the video card and how much is due to the TV. The parameters for xrandr came from a LLM because I couldn’t find any Google results on what 8K parameters to use. As an aside if you have a working 8K TV or monitor connected to a computer please publish the EDID data, xrandr, and everything else you can think of.
I found a Github repository for EDID data [5] but that didn’t have an entry for my TV and didn’t appear to have any other entry for an 8K device I could use.
Resolution for Web Browsing
I installed a browser on the TV, Chrome and Firefox aren’t available for a TV and the Play Store program tells you that (but without providing a reason) when you search for them. I tried the site CodeShack What is my Screen Resolution [6] which said that my laptop is 2460*1353 while the laptop display is actually 2560*1440. So apparently I have 100 pixels used for the KDE panel at the left of the screen and 87 pixels used by the Chrome tabs and URL bar – which seems about right. My Note 9 phone reports 384*661 out of it’s 2960*1440 display so it seems that Chrome on my phone is running web sites at 4/15 of the native resolution and about 16% of the height of the screen is used by the system notification bar, the back/home/tasklist buttons (I choose buttons instead of swipe for navigation in system settings), and the URL bar when I have “Screen zoom” in system settings at 1/4. When I changed “Screen zoom” to 0/4 the claimed resolution changed to 411*717 (2/7 of the native resolution). Font size changes didn’t change the claimed resolution. The claimed “Browser Viewport Size” by CodeShack is 1280*720 which is 1/6 of the real horizontal resolution and slightly more than 1/6 of the vertical resolution, it claims that the Pixel Density is 2* and a screen resolution of 970*540 which means to imply that the browser is only working at 1920*1080 resolution!
Netflix
When I view Netflix shows using the Netflix app running on the TV is reports “4K” which doesn’t happen on Linux PCs (as they restrict 4K content to platforms with DRM) and in the “Device” setting it reports “Device Model” as “Hisense_SmartTV 8K FFM” so the Netflix app knows all about 4K content and knows the text string “8K”.
YouTube
When I view a YouTube video that’s described as being 8K I don’t get a request for paying for YouTube Premium which is apparently what happens nowadays when you try to play actual 8K video. I turn on “State for Nerds” and one line has “Viewport / Frames 1920×1080*2.00” and another has “Current / Optimal Res 3840×2160@60 / 3840×2160@60” so it seems that the YouTube app is seeing the screen as 4K but choosing to only display FullHD even when I have Quality set to “2160p60 HDR”. It declares the network speed to be over 100mbit most of the time and the lowest it gets is 60mbit while 50mbit is allegedly what’s required for 8K.
I installed a few Android apps to report hardware capabilities and they reported the screen resolution to be 1920*1080.
Have I Been Ripped Off?
It looks like I might have been ripped off by this. I can’t get any app other than Netflix to display 4K content. My PC will only connect to it at 4K. Android apps (including YouTube) regard it as 1920*1080.
The “AI Upscaling” isn’t really that great and in most ways it seems at best equivalent to a 4K TV and less than a 4K TV that runs Android apps with an actual 4K display buffer.
Next Steps
The next things I plan to do are to continue attempts to get the TV to do what it’s claimed to be capable of, either an Android app that can display 8K content or a HDMI input of 8K content will do. Running a VNC client on the TV would be an acceptable way of getting an 8K display from a Linux PC.
I need to get a somewhat portable device that can give 8K signal output. Maybe a mini PC with a powerful GPU or maybe one of those ARM boards that’s designed to drive an 8K sign. Then I can hunt for stores that have 8K TVs on display.
It would be nice if someone made a USB device that does 8K video output – NOT a USB-C DisplayPort alternative mode that uses the video hardware on the laptop. Then I could take a laptop to any place that has an 8K display to show and connect my laptop to it.
The one thing I haven’t done yet is testing 8K MP4 files on a USB stick. That’s mainly due to a lack of content and the fact that none of the phone cameras I have access to can do 8K video. I will try displaying 8K PNG and JPEG files from a USB stick.
Most people would give up about now. But I am determined to solve this and buying another large TV isn’t out of the question.
- [1] https://etbe.coker.com.au/2024/12/15/hisense-65u80g-8k-tv/
- [2] https://etbe.coker.com.au/2025/03/06/8k-video-cards/
- [3] https://lemmy.ml/post/38586188
- [4] https://en.wikipedia.org/wiki/Extended_Display_Identification_Data
- [5] https://github.com/linuxhw/EDID
- [6] https://codeshack.io/what-is-my-screen-resolution/
Have you got yourself an 8K certified cable, as this will help with the issue, as it may not be compatible with the required HDMI standard? Also is the graphics card chosen, also compatible with the HDMI standard and also 8K ready (or certified)?
Also some settings may need to be altered in Debian so that the functionality goes active!
Worth checking and trying these individually but recommended being done together!
Also if you’re looking to do it wirelessly checkout Miracast support either in the TV, or in a small form computer either Raspberry Pi 4 or 5. Alternatively a small form factor device running the appropriate Miracast software. Another alternative is to use an open source equivalent (if feasible) to Google Chromecast.
If you’re on Debian 12 then how about giving Debian 13 ago on at least 1 computer! As this will give the system a newer kernel, and possibly a newer version of the drivers for the graphics card. The 8K resolution picture quality may only be available in a newer version of the graphics card drivers.
Also if the motherboard supports it make sure, ResizableBAR is enabled the drivers for your Intel Arc graphics card perform best when it’s enabled!!
I have tried several cables that are described on the box as 8K certified, some vendors may lie about the cable capabilities but I doubt all would and any cable which can do 4K at 120Hz (which has never been a problem for me) should do 8K at 30Hz! Would it change the EDID output based on the cable plugged in?
Chromecast or similar still requires a device sending an 8K HDMI signal which I haven’t been able to get working.
I’m running Debian/Unstable so it has quite recent drivers, currently running 6.16.12+deb14+1-amd64.
The system gives a warning about BAR size on boot but the BIOS doesn’t have an option to change it. It’s a HP z840. Performance doesn’t matter for me. The main thing I want to do is co-working so I’d like to have lots of source code displayed on the screen at one time.
Thanks for all the comments.
You may have to pay for them to come via international post but Rhino Cables (https://rhinocables.co.uk/) are serving and sold me some very good quality cables. They even supplied me with an 8K capable HDMI cable, that enabled me to get the best performance out of my qHD FreeSync enabled gaming monitor on my computer.
They also supply other cables and leads, the company is a family owned and run business.
Make sure to go to the HDMI cables section, as the ones they’re a certified or guaranteed to be 8K compatible. Also this will affect the bandwidth – get you to the speed required for 8K. If bandwidth is part of EDID data, then yes it will change it because the results of bandwidth tests change.
Performance does matter on the graphics card for 8K, as it’s the source of the data, can’t get to 8K on TV if it’s not sent fast enough!
Make sure the HP has its BIOS updated to 02.59 Rev.A. Then hunt through the BIOS for any new options, to see if there’s been any additions for ResizeBAR.
Any way make sure the BIOS is updated via fwupd or the HP z840 support page.
To get to 8K video the cable needs to be able to transfer around 48 GB/s from graphics card, to display (monitor or TV).
Rhino cables have at least one which can achieve this transfer rate, also important to consider the length of cable and distance from computer to TV.
This is what I’m running:
root@usagi:~# fwupdmgr update
Devices with the latest available firmware version:
• UEFI CA
• UEFI dbx
• KXG60ZNV512G NVMe TOSHIBA 512GB
• PC601 NVMe SK hynix 1TB
Devices with no available firmware updates:
• HP UEFI Secure Boot 2013 DB key
• Hewlett-Packard UEFI Secure Boot DB Key
• Option ROM UEFI CA
• TPM
• Windows Production PCA
• Arc B580
• Arc B580 (Data)
• Arc B580 (OptionROM Code)
• Arc B580 (OptionROM Data)
• CT1000P3PSSD8
• CT1000P3PSSD8
• Hewlett-Packard UEFI Secure Boot Key Exchange Key
• KEK CA
• LK0480GFJSK
• SSD 860 QVO 1TB
• SSDSCKKW480H6
• System Firmware
From dmidecode:
BIOS Information
Vendor: Hewlett-Packard
Version: M60 v02.59
Release Date: 03/31/2022
So it’s a matter of the cable used as if it’s not certified for 8K, HDMI 2.1 and high performance (46 GB/s transfer rate). Then you won’t be able to get 8K.
Also drop X.org as graphics engine only use Wayland – has 8K support. Need to use KDE or Gnome.
Make sure on Gnome you’re using versions (40+) best with either 46 or 49. Alternatively on KDE using versions from KDE Plasma 6.x (best with 6.5 or later).
Also check that the resolution configured in desktop environment is for the 8K native of the TV. If the native for 8K is non-standard it may need to be added.
The changelog for 2.59A doesn’t mention BAR resize, I don’t think I need that performance, and the 2.59A download requires the Linux kernel drivers that I don’t want to install so I don’t plan to install this. Thanks for the suggestion though, it’s worth checking such things.
I think that the evidence so far suggests that the cable is not the problem.
In the monitor range limits section the minimum vfreq is 24Hz and the maximum hfreq is 81KHz so 81000/24 means 3375 is the maximum number of lines per screen, not the 4320 needed for 8K resolution. I couldn’t find anything about cable frequency in EDID.
The EDID only says 30Hz at 4K resolution which is definitely way below what the cable could do.
With the workstation’s BIOS it seems that fwupd, doesn’t seem to be seeing the updates after 2.59! As the fwupd website lists 2.61 and 2.62 versions.
Which is more than a bit odd!
https://fwupd.org/lvfs/devices/com.hp.workstation.M60.firmware
Checking for updates for the Hisense may help as if there’s any bugs, with sorting out 8K fixed they may not have been applied. If the TV isn’t connected to anything which would enable the updates application.
The TV is Android based so there’s potentially a series of updates, waiting so if any bugs are preventing 8K it may be part of the issue. Make sure the TV is updated to the latest software bugs can affect EDID reading and HDMI compatibility.
Also have you enabled “Enhanced Format” for the HDMI port being used? If not please try enabling it for that specific port, without enabling it the content potential is limited to 4K by design.
You MUST have and use a Certified Ultra High Speed 8K capable cable not a 4K capable one, or a standard one. Using a 4K or standard cable has the capacity to corrupt the EDID handshake causing this very 4K only limit issue.
Make sure that you are using an HDMI 2.1 compatible port on the TV as apparently only certain ones support the spec. Try switch the ports, as well as changing the format setting.
Make sure the cable isn’t too long, as this affects signal integrity shorter ones improve the signal integrity. So consider moving the placement of the TV and workstation so that the cable can be shorter. Also consider a higher quality shorter cable.
Check Workstation screen resolution is set to “7680 x 4320” or has auto detect enabled. Make sure that HDR is enabled for your computer.
Power cycling the devices can be necessary to re-establish EDID handshake correctly.
That’s strange, in addition to the z840 running Unstable I have two z640 systems running Trixie which are also on BIOS 2.59 and with no reported updates.
You can manually download the update CAB file from the link on the fwupd.org site and save it somewhere on the system. Then with a terminal or command prompt type “fwupdmgr install ”.
This will cause fwupd to apply the firmware update using the locally downloaded update. Also have you done the other steps, yet involving the PC and TV. All of them are necessary, especially checking settings on the TV and applying updates to its firmware and software.