This works fine in general (the Lenovo monitors run fine at 1440p 144Hz, USB migrates fine between the systems, keyboard shortcuts work as expected) however there are a few annoying issues:
The worst is that when switching between PCs the OS thinks that the monitors have completely disconnected from it. This happens on both Windows and Linux. The FAQ page ([Official] L1Techs KVM FAQ -- Ultimate Guide & Help!) says:
If you have a need to have a game open, but want to prevent the game from detecting the monitor has changed when the input has changed, then this KVM will also work for that scenario. We had several game developers using the DP1.4 KVM that has asked specifically for this feature to aid in game development.
however this doesn’t seem to actually happen on my KVM.
The Lenovo monitors never “wake up” if they go to sleep/power saving mode (the LG monitor however wakes up just fine). This means that if I leave the OS idle or have to reboot the active PC I need to power-cycle both of them to get them to be detected again.
When switching between computers (either via the button on the KVM or via keyboard shortcut) it sometimes happens that certain keys/buttons on the mouse and keyboard stop working (the back/forward side buttons on the mouse, the Insert/Del/Home/End/PgUp/PgDown cluster on the keyboard). I can get them to work again by either power cycling the keboard/mouse OR unplugging/plugging in the receiver from the HID USB port. This problem never happens if I have the receiver plugged into the USB 3.2 port on the KVM (but obviously then I also lose keyboard shortcut support).
Any tips on how to solve these issues would be greatly appreciated.
The keypad can be programmed with whatever keys you need for switching (e.g. scroll lock, and number 1, 2). I also added a volume up down and mute to my 9 key keypad.
Plug that into the HID port and use it for switching instead of your usual keyboard.
What you’re referring to here is a different KVM than what you’ve bought, unfortunately. This is under the “EDID (Monitor Emulation) KVMs - DisplayPort 1.2” section of the FAQ. The particular KVM this quote is from, and our HDMI 2.1 KVMs, are the only L1Techs KVMs that have monitor emulation. If this is what you’re wanting, you can achieve monitor emulation in software (linked/explained in the FAQ), or, via hardware like this:
Sounds like an issue with either 1. the monitors settings or 2. video drivers. A power saver / eco mode could be causing it. I would also DDU and reinstall your video drivers. I would also update your monitor’s firmware as apart of troubleshooting.
Check if uninstalling the logitech software form your all computers fixes your issue, then power cycle the KVM. HID is a driverless standard. The Logitech software and HID standard can conflict with each other. The reason the blue USB ports work is because they are hard cutover and not HID.
What you’re referring to here is a different KVM than what you’ve bought, unfortunately. This is under the “EDID (Monitor Emulation) KVMs - DisplayPort 1.2” section of the FAQ.
While that’s true it also clearly references DP1.4 KVMs. I hope you can see how it can by confusing, I just interpreted it as the DP1.4 KVMs that are on the store having this feature.
Adding the DP repeaters is not really feasible, I simply have no good way of providing 3 extra power outlets at my desk. Maybe if they could be somehow powered from the USB ports on the back of the KVM.
Sounds like an issue with either 1. the monitors settings or 2. video drivers. A power saver / eco mode could be causing it. I would also DDU and reinstall your video drivers. I would also update your monitor’s firmware as apart of troubleshooting.
I’ve looked through the monitor settings, I can’t see any “eco mode” or “power saving” mode toggles. As for DDU - I don’t see how that’s applicable as this issue happens on the Linux system as well.
In terms of firmware updates - I’ve looked into it a few months ago for unrelated reasons and I couldn’t find any, I can try searching again I guess.
Check if uninstalling the logitech software form your all computers fixes your issue, then power cycle the KVM.
I can certainly try, but again, this happens with the Linux system as well so I’m not sure of the relevance.
Hm, if you’re referencing that paragraph specifically, the DP 1.4 KVM incompatibility is mentioned as a reason we created the DP 1.2 monitor emulation version. People who had DP 1.4 KVMs requested a KVM with monitor emulation.
That’s possible they could be powered via the KVM. The best fix for monitor emulation is in software, though. I’d have to ask Wendell about Linux, but in Windows 11 there’s a toggle in the display settings and in windows 10 there’s the “persistant windows” repository on github.
@wendell do you have any insight about these issues:
this is an indication there is a software mismatch on the host. logtitech can use an 8 or 20 byte usb protocol for hid, which are technically both standard, but they dont easily switch betweent hese protocols. usb3 port does a full bus reset so it doesnt matter. if you can get both machines to use either the 8 or 20 byte protocol, usually matching software installed (or not) then this problem will go away. the numlock on/off work around was the fix for old unifying receivers, but newer receivers (i.e. since 2019?) don’t have this bug? how old is the wireless dongle you’re using? do you have a different one you can pair with? is it unifying or something else?
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this is pretty odd. anything useful in the osd of these monitors? maybe power save, eco mode, fast handshake? anything about dp protocol version? sleep mode?
It’s clear that I misinterpreted the FAQ page, it is what it is. Maybe it’s worth trying to trim down some of the “fluff” in there, there are enough details to keep track of without all of the “embellishments”.
The receiver is not branded as “Unifying”, it’s the newer “Bolt” variant (Logi Bolt USB Receiver for Multi-Computer / Device Use - not sure if it’s just a rebrand of the older “Unifying” ones or it’s actually something different; at least externally they look different). I actually have 3 of them (bought in April 2023), I’ve been using them to switch between my PCs and my laptop. The issue only happens when one of these receivers is “transferred” between the PCs by the KVM, and only when plugged in the front HID port of the KVM (I haven’t tested any of the other HID ports). I would agree with a possible software cause HOWEVER I can work around the issue by forcing a re-pair between the keyboard/mouse and the receiver (by power-cycling the keyboard/mouse), so no actual USB disconnect on the host computer occurs. It’s possible it’s a firmware bug on the receiver itself, but I doubt it’s something on the PCs that’s causing it (again, one of the PCs is Linux so no Logitech software to speak of).
I haven’t seen any options relating to the sleep/power saving/“eco mode” behavior. There is an option to switch between DP 1.2 and 1.4, both monitors are set to 1.4.
