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More About Kogan 5120*2160 Monitor

On the 18th of May I blogged about my new 5120*2160 monitor [1]. One thing I noted was that one Netflix movie had run in an aspect ratio that used all space on the monitor. I still don’t know if the movie in question was cropped in a letterbox manner but other Netflix shows in “full screen” mode don’t extend to both edges. Also one movie I downloaded as in 3840*1608 resolution which is almost exactly the same aspect ratio as my monitor. I wonder if some company is using 5120*2160 screens for TVs, 4K and FullHD are rumoured to be cheaper than most other resolutions partly due to TV technology being used for monitors. There is the Anamorphic Format of between 2.35:1 and 2.40:1 [2] which is a close match for the 2.37:1 of my new monitor.

I tried out the HDMI audio on a Dell laptop and my Thinkpad Yoga Gen3 and found it to be of poor quality, it seemed limited to 2560*1440, at this time I’m not sure how much of the fault is due to the laptops and how much is due to the monitor. The monitor docs state that it needs HDMI version 2.1 which was released in 2017 and my Thinkpad Yoga Gen3 was released in 2018 so probably doesn’t have that. The HDMI cable in question did 4K resolution on my previous monitor so it should all work at a minimum of 4K resolution.

The switching between inputs is a problem. If I switch between DisplayPort for my PC and HDMI for a laptop the monitor will usually timeout before the laptop establishes a connection and then switch back to the DisplayPort input. So far I have had to physically disconnect the input source I don’t want to use. The DisplayPort switch that I’ve used doesn’t seem designed to work with resolutions higher than 4K.

I’ve bought a new USB-C dock which is described as doing 8K which means that as my Thinkpad is described as supporting 5120×2880@60Hz over USB-C I should be able to get 5120*2160 without any problems, however for unknown reasons I only get 4K. For work I’m using a Dell Latitude 7400 2in1 that’s apparently only capable of 4096*2304 @24 Hz which is less pixels than 5120*2160 and it will also only do 4K resolution. But for both those cases it’s still a significant improvement over 2560*1440. I tested with a Dell Latitude 7440 which gave the full 5120*2160 resolution, I was unable to find specs on what the maximum resolution of the 7440 is. I also have bought DisplayPort switch rated at 8K resolution. I got a switch that doesn’t also do USB because the ones that do 8K resolution and USB are about $70. The only KVM switch I saw for 8K resolution at a reasonable price was one designed for switching between two laptops and there doesn’t seem to be any adaptors to convert from regular DisplayPort to USB-C alternative mode so that wasn’t viable. Currently I have the old KVM switch used for USB only (for keyboard and mouse) and the new switch which only does DisplayPort. So I have two buttons to push when switching between input sources which isn’t too bad.

It seems that for PCs resolutions with more pixels than 4K are as difficult and inconvenient now as 4K was 6 years ago when I started doing it. If you want higher than 4K resolution to just work at this time then you need Apple hardware.

The monitor has a series of modes for different types of output, I’ve found “standard” to be good for text and “movie” to be good for watching movies/TV and for playing RTS games. I previously wrote about how to use ddcutil to use a monitor as a KVM switch [3], unfortunately I can’t do this with the new monitor as the time that the monitor waits for a good signal on a new input after changing is shorter than the time taken for Linux on the laptops I’m using to enable HDMI output. I’ve found the following commands to do the basics.

# get display mode
ddcutil getvcp DC
# set standard mode
ddcutil setvcp DC 0
# set movie mode
ddcutil setvcp DC 03

Now that I have that going the next thing I want to do is to have it switch between “standard” and “movie” modes when I switch keyboard focus.

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