U3225QE, two Mac Studio, KVM switching delay, mouse, keyboard

Question

Hi everyone,

I’m using a Dell U3225QE with two Mac Studio units connected for KVM usage. One Mac Studio is connected via USB-C (Thunderbolt) and the other via HDMI.

I have a Logitech MX Keys keyboard and a Logitech MX Master 3S mouse connected directly to the monitor’s USB ports for KVM switching.

The issue I’m experiencing:
When switching input from USB-C (Mac 1) to HDMI (Mac 2), the keyboard and mouse take around 2–3 seconds to be recognized by the second Mac.

After the switch, the video input changes immediately, but USB peripherals are not instantly available on the target Mac. There is a short delay before input starts working.

Is this expected behavior for the U3225QE KVM implementation?

Or is there any setting/firmware adjustment to make USB switching instantaneous?

Thanks in advance for any insights.

cetinbey · Accepted Answer

I’ve managed to solve this issue.

I stopped using the USB-C to USB-A upstream cable that came with the monitor for KVM and switched to a direct USB-C to USB-C connection instead.

Since then, the switching delay between the two Macs (keyboard/mouse recognition) has been eliminated and everything works instantly when changing inputs.

So in my case, the issue was related to the USB-A based upstream path. Using a native USB-C upstream connection fixed it completely.

Hope this helps anyone experiencing the same behavior.

DELL-Daniel V · Answer

The short delay is going to be likely the result of the KVM controller switching units, so a design limitation. You could update the monitors firmware, but I wouldn't really expect that to make for an instantaneous switch.

U3225QE Drivers. Ensure the Filter is set to Mac OS. Users on Windows may even see the same situation which would reaffirm this to be a design limitation and not an OS one.

cetinbey · Answer

@DELL-Daniel V​  Hi, Thanks for your response. I’ve already updated the monitor to the latest firmware, but the switching delay (around 2–3 seconds) remains unchanged. I understand that some delay might be inherent to the KVM controller design. However, I’d like to add an important comparison point: I purchased the U3225QE about 1–2 weeks ago. Before this, I was using an LG34WQ75C monitor with the exact same setup (two Mac Studio devices, same keyboard and mouse connected to the monitor for KVM). On that monitor, KVM switching was effectively instantaneous — there was no noticeable delay when switching inputs, and the keyboard/mouse were immediately available on the target machine. Because of that, this behavior on the U3225QE feels noticeably slower and less seamless. So I’m trying to understand: Is this delay truly expected for this specific model’s KVM implementation? Or could there still be a configuration, firmware, or compatibility factor affecting USB switching performance? Appreciate your clarification.

DELL-Daniel V · Answer

@cetinbey​ Without testing this monitor on different systems, then it'd be hard to confirm the expected result. I'd recommend posting this in the Apple forums to see if other users are running into the same thing. Since its a short delay, then I would have to imagine thats the expected result for this monitor. The LG could simply have a better implementation but again we'd need more systems to be tested to really confirm what should be expected.

githit · Answer

I find switching inputs on the U3225QE to be a complete lottery. Most of the time it gets stuck scanning for devices (PC with 5060Ti DP, MBP with Thunderbolt). When not failing to detect a signal, it causes Windows 11 to report USB errors and the PC has to be rebooted to resolve those. The U3415W that the U3225QE replaced here was actually able to switch between inputs reliably.

I don't think the integrated KVM should be listed as a feature. I am saving up to replace this terrible bit of kit. I wouldn't feel good giving it away.

Monitors

U3225QE, two Mac Studio, KVM switching delay, mouse, keyboard

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