DIY 5k Monitor - success :-)

[8megabits]

Thank you!
I don't have any more powerful PSU, but I have ordered a 10A one arriving later this week.
I also ordered a power usage meter.
I'll do some experimentation and report back.

Previously I have tested the Macbook power draw with a USB power meter, with the following results (when the Macbook battery is on low charge):

• Only plugging in USB-C: Macbook draws ~80W.
• Plugging in both Displayport and USB-C: Macbook draws ~40W. The USB-C connection still dies if I put the display on high brightness in this scenario.
• Plugging in Displayport and then USB-C through a dongle: Macbook draws ~20W. This was stable with high brightness if I recall correctly.

I can confirm that the problem seemed to be that the 6A PSU was too weak. With 8A and 10A PSUs it worked fine.

I did some measurements to check the power draw from the outlet, the peak I saw with USB-C charging on low battery + 100% display brightness was around 165W. So if you want to use the 90W charging over USB-C you need at least an 8A / 24V PSU.

On full battery charge the draw over USB-C was around 30W with 0% brightness, and 75W with 100% brightness.

With Displayport (meaning the display is not powering the computer) the draw was around 20W with 0% brightness, and 65W with 100% brightness.

Maybe this can help someone else too!

 

[PaulD-UK]

@8megabits
"With Displayport (meaning the display is not powering the computer) the draw was around 20W with 0% brightness, and 65W with 100% brightness."

Thank you for giving details of the power consumption of the JRY-W9RQQHD-SA1.

For comparison here are the same figures for my R1811 HDMI 2.0 board:
Backlight 0%: 22.5W.
Backlight 50%: 33W.
Backlight 100%: 52.5W.
Sleeping: <1W.

For the Haijing T18 board, which was tested here:
Display on (0% backlight brightness, which is still "on" and visible, just low): 25W
Display on (50% backlight brightness, the default value): 72W
Display on (100% backlight brightness): 82W
Display connected but in sleep (no backlight, red LED lit on the button board): <1W

For comparison, the Apple Studio Display is listed as only using 21.2 watts in use.