MacBook Pro M3 Max Display flickers to black every few minutes or video artifact flickers on screen. 3440x1440 monitor. KVM works without issue on PC connected via DP cable. Flickering goes away when MacBook Pro set to 60Hz. 120Hz or 240Hz causes described issues.
Other Notes:
Tried multiple high quality USB-C/USB4/Thunberbolt 4 cables (both 2m and 1m lengths) from Club 3D, Cable Matters, and even official Apple Thunderbolt 4 Pro 1m cable, same issues. All DP cables used in the chain are 1m Club3D DP2.1 UHBR20 rated cables. Used to run without issue on prior 2560x1440 monitor at 144Hz using a Club3D 2m USB-4 cable, and fairly positive this worked in the beginning with this new monitor connected using that same cable (which subsequently over time has started having the flicker issues, along with other cables mentioned above having same issues). So it seems like something has been deteriorating over time.
Mac is connected via the single USB-C cable into KVM. Using a single monitor. No PIP utility used. Signal path is: USB-C out from MacBook Pro into KVM (PC2 USB-C port) > PC 2 DP-Out port into PC1 DP-In#2 port > PC1 DP-Out port into monitor. Each DP cable used is the aforementioned Club3D UHBR20 rated 1m cables.
Why not just USB-C out from MacBook Pro into KVM (PC2 USB-C port) > PC 2 DP-Out port into your monitor? Why are you looping it through the KVM twice? That’s just degredating bandwidth…?
It sounds like you have an unnecessary 1m (3ft) connection going from DP 2 out to PC 1 in. So, try it how I suggested as an experiment to see if the video fidelity improves. If it works as intended with the test we can assume there is a bandwidth issue.
Monitor has a single DP 1.4 port, so I can’t have two DP connections from KVM to monitor. I’m going to try switching the Mac to be PC 1 though, since that would still remove the extra loop for that signal path.
Is there some kind of known issue with M3 Max Macs? Or is it possible to arrange a swap of the KVM? Or should I buy a second KVM and see if I have the same issues? I’m trying to figure out best options to continue troubleshooting here.
Yes, this was taken with the MacBook USB-C out > PC1 In > PC1 Out setup.
I have moments where everything seems to work without issue for long periods of time (like I just experienced with 45 minutes of coding on the Mac with zero display problems), but 100% of the time if I swap to the PC, do some work, then switch back to the Mac, the problems seem to start. If I disconnect the cable entirely from the KVM and the Mac, wait a few moments, then reconnect, seems to work without issue. But yesterday I was having issues even getting that to work, so I need to test this more.
So, sleep issues are usually either settings or display driver-related. The first thing I would try reinstalling your drivers. Can you disable sleep for testing?
What drivers would I even reinstall for Mac OS? I didn’t install any drivers to begin with. I’ve also tested in Safe Mode and on a fresh account and have the same issue.
I’m going to do more testing tonight and will update then. Thanks for the the help so far.
yeah we can setup mail in RMA but it may be worth trying $7 of ferrite cable clamps. maybe on the monitor cable where it exists the kvm. that it works till switch is very odd, some kind of training issue maybe which the kvm shouldn’t really interfere with. the who mo of the kvm is to try to be as transparent to the gpu and display as possible.
what firmware on the monitor /is it latest? we had loads of issues from our g9 I had to harass Samsung to get bugs fixed
Hello, just wanted to update. I’m having consistent connection issues with my USB devices now. I think I would like to pursue an advanced RMA, I don’t mind paying for a second unit and getting a refund after you receive the one I currently have. There’s just a lot of weirdness happening that I haven’t experienced before.
