Seeking answer to power issues on MacBook pro - Solved !

[Sootchucker]

Hi guys. I've just purchased a Dell U2725QE Thunderbolt 4 27" monitor for my upstairs Mac Book Pro (16" M1 Max version), but I've having a few difficulties with a specific problem that I'm hoping someone could assist with.

So, I have my 2.5Gbe ethernet cable plugged into the Monitor, and then the Monitor is plugged into the MBP via the thunderbolt 4 Upstream socket directly into one of the MPB's Thunderbolt ports (so effectively I'm accessing internet over the Thunderbolt cable). So far so good, the picture is beautiful, ethernet works as expected. However, I have an 8TB Thunderbolt NVME external enclosure also plugged into the MPB. I'm trying to back up a very large amount of data from my NAS (located in my study downstairs (and also on 2.5Gbe), I can see the NAS on the MBP, and I start copying the files.

As the transfer process will take several hours, I then put the monitor into standby mode, and within 10-20 seconds the light on the external drive stops flashing, and on examination it seems that when I turn the monitor off, it seems to be cutting the ethernet to the MPB, and so it both stops transfer and obviously loses connection to the NAS downstairs. According to Dell's documentation:

"the Dell U2725QE's Ethernet port is part of the monitor's built-in hub and does not require the monitor to be switched off to disconnect your network connection; it is managed by the power state of the monitor itself and the connected computer."

Am I doing something really dumb - anyone any ideas as I really don't want to leave the monitor on all the time ?

 

[Box Brownie]

None too sure but out of curiosity I found this that may point you on a good direction?

Google Search

 

[Sootchucker]

Just to update and close this thread I solved the problem.

Firstly the issue with putting the monitor into standby mode was user error. I though hitting the power button on the Dell monitor put it into standby mode, but in fact turns the monitor completely off cutting the power to the TB port and thus disconnecting the from Mac. If I just leave my mac to go to sleep after a short time of inactivity, then the monitor also goes to sleep but keeps the power and data connections live to the mac. Doh !!!

I also located another issue whilst testing, and that was when I figured the above out, I noticed that whilst the copy of files from the NAS continued perfectly after the monitor and MBP went to sleep, it was painfully slow despite the monitor, cables, NAS and switch all being 2.5GBe ones, I was getting transfers of around 10-15Mb sec (painfully slow when transferring TB's of data - It was saying nearly 2 days for 3.6TB). The issue was that I recently equipped my QNAP NAS with two 1TB NVME drives to act as cache acceleration, but for some reason that was the issue. When I disabled Cache acceleration and then removed the NVME sticks, I tried again. This time the copies were at 150-260MB/Sec (which is about what I expected from a 2.5GBe network), and the copy only took just over 4½ hours to complete !