Dummy HDMI adapters

A nice adapter that has both input and output is this which i got from AliExpress (Photos at the bottom)

This 4K dummy adapter seems to support all resolutions up to 60Hz refresh rate, with the exception of 4K which works at a maximum of 30Hz (Probably due to signal attenuation)

There are many uses for this dummy adapter, one of them is “Sunshine and moonlight remote desktop”, another is using your GPU for processing while you are away (Nvidia won’t allow it if you don’t have a monitor connected and switched on), and most importantly TO ME, My video switch since I use multiple machines on the same monitor.

What this adapter is in reality is an eeprom chip that has the EDID data of a monitor with a very high refresh rate (120 hz), namely a fictitious monitor named AOC 28E850, If you want to make sure that this works with your monitor, it needs to be flashed with your monitor’s EDID.

If your monitor supports 4K at 60hz, you need to keep everything in that copy, and remove the 4K.60Hz from the list

If you want the modified file that originated from my LG 27UL550 and was modified to remove the 60Hz from the list of supported configurations, meaning I removed the 60 FPS from the 4K DTD, then here it is, just download it and flash it (Flashing instructions below) I also changed the monitor’s name just in case some systems might cache it’s details…

The steps

1- Find out the port on your graphics card that your monitor is connected to

2- Copy the EDID data from your monitor

3- Edit the data to remove the 4K/60 fps
4- Burn the data onto the adapter

To do that, there are many tools, one thing to note is that edid-rw did not work using my laptop which has a 9400mx, but worked just fine using an old PC i have with a “GT218 [GeForce 210]”, the error on the laptop reads

sudo ./edid-rw 5
Traceback (most recent call last):
File “./edid-rw”, line 131, in
main()
File “./edid-rw”, line 119, in main
edid = [dev.read(i) for i in range(EDID_HDR)]
File “./edid-rw”, line 46, in read
return self.smb.read_byte_data(EDID_ADDR, n)
IOError: [Errno 110] Connection timed out

edid-rw tool: https://github.com/bulletmark/edid-rw
wxedid tool: install from debian repo

I personally used the tools above to read/write/edit, but if you have access to a windows machine, AW-EDID should be the best tool for editing….
Analog Way EDID editor: https://www.analogway.com/apac/products/software-tools/aw-edid-editor/

So, let’s get down to that voodoo business !

1- There seems to be a very cool python script (tool) called edid-rw, let us install it’s prerequisites

sudo apt-get install python3-smbus edid-decode git

Now, you have python, let us download the tool, you can do that with the download button on github, I would rather just

git clone https://github.com/bulletmark/edid-rw
cd edid-rw

To begin with, you may need to run the following command to see what monitors are connected where, In my case, the monitor I want to copy (LG 4K 60FPS) is #5

xrandr --query

If this does not help, try the numbers and read the output to see which entry corresponds to the screen you want
sudo ./edid-rw 5 | edid-decode

Now that we have it, we can edit it with one of the software mentioned above, and dump it back on the dongle (The port number does not change, so put your number there and dump the data onto it)

udo ./edid-rw -w 5 < ~/edited_lgedid.bin

Text from the original page of the item

Support hot plug, plug and play
Support virtual display, when the display is powered off or the display cable is hot-plugged, It can achieve no video signal loss, no screen change, no windows running, no order disorder;
Support up to 10.8Gbps video bandwidth; It has power-off memory function, power-off/restart display sequence is not chaotic, and the set mode is not lost.
Supports for AMD multi-screen image card splicing extended split-screen mode, eyefinity wide-area multi-screen splicing mode (pulling the monitor cable when it is powered on has no effect on the display of the screen TV wall, and pulling the line will only cause the screen of the dropped line to be black, and other screens will not move)
Support Nvidia image card multi-screen output, the screen sequence is not chaotic after restart

Connect typ:HDMI
Application scope: Display with HDMI interface
Product name :HDMI lock screen treasure
Max Resolution : 2560 x 1440@60HZ / 3840 x 2160@60HZ
colour:Golden
Material:Aluminum alloy

Package Contents:
6 x HDMI2.0 Virtual Adapter

The aluminum sleeve appears to be fully cosmetic, At least this is my impression as the plastic inside seems very hard, so it is unlikely that the aluminum is providing any support, and obviously is not functioning as any form of heat sink

LG UL550 vs the ASUS VP28UQGL

Update: the official winner in this is the ASUS, mainly for having built in speakers
Update: After buying the LG for myself and the ASUS for a friend, The ASUS does pivot 90 degrees as well !!! the only real advantage i see in the LG is the IPS display (Color accuracy for graphics designers that you will not be able to detect with the untrained eye)

Because the place where i buy my monitors currently only has 2 4K monitors in the 27″ category, I had to compare them to pick one, for most people the ASUS is the clear winner, unless you are a graphics designer, then it is the LG (IPS has better color), I will probably buy the LG because of it’s Pivot feature (UPDATE-They both have pivot), but most people would want the ASUS, in any case, here are the specs for both side by side

The reason the LG is more expensive is because it has IPS, IPS has only one advantage, color, and only to a degree that affects a graphics designer, in fact, IPS has disadvantages too compared to TN (twisted nematic).

Feature ASUS VP28UQGL lg ul550
PRICE 259 JOD ($249 at amazon) 275 JOD ($326 at amazon)
SIZE 28 (620.93 x 341.28 mm) 27
Response time (True native) TN is usually faster, but not mentioned 5ms
Response time (GTG) 1ms 1ms
Panel Type TN (twisted nematic) / LED IPS (in-plane switching)
Resolution 3840×2160 3840 x 2160
Pixel Pitch (mm) 0.160mm 0.1554 x 0.1554 mm
Refresh Rate 60Hz 60Hz
USB Video no no
USB HUB no no
HDMI 3 (2.0) but can only find 2 in manual, manual is for whole series 2 (No mentioning, but most likely 2.0a or 2.1)
DP 1 = 1 (1.2) 1 (No mentioning of Version)
HEADPHONE 1 1
BRIGHTNESS 300cd/㎡ 300cd (typ) / 240cd (Min)
CONTRAST 1000:1 (MIN/TYP) 700:1 (Min.), 1000:1 (Typ.)
COLOR 10BIT (1073.7M) – 94%sRGB IPS has better color
HDR   10
Power Consumption (Typ.) <31 36 – 41
POSITIONS Tilt : Yes (+20° ~ -5°), Pivot(Not auto) Tilt (3°)/Height (Lower and raise)/Pivot(Not auto)
VESA MOUNTING NO YES
NVIDIA/AMD Radeon FreeSync Radeon FreeSync™
SPEAKERS` YES 2W X 2 NO
Buttons Joystick Joystick
power adapter Internal (Thicker, and less heat management) external, 19v, 2a
dimensions with stand 660.4 x 672.5 x 226.3 mm 622.6 mm x 572.2 mm x 230.0 mm
dimensions without stand 660.4 x 380.8 x 62.2 mm 622.6 mm x 371.0 mm x 45.8 mm
Blue light filter Yes No
OSD Nicer and easier Does the job perfectly, but less nice

The stand is also something i like about the LG, even though it takes more space on the desk, the space is not completely taken by the stand, the half oval shape allows you to put your things on the table within the stand, it also has some height adjustment (just a bit, for the portrait pivot mode mostly so it is not so much a standing desk in any way) that allows me to raise it a bit when i need to for more comfort