Lag / Sensitivity impact on mouse through KVM. (+FIX)

I’ve been using the KVM (2x dp1.4) for a couple of days now and on 1 of the 2 computers I get irregular mouse sensitivity.

At seemingly random times the sensitivity of my mouse will drop significantly for about 3 seconds.
This happens very often, like every minute, and is very annoying.

Using MouseMovementRecorder I spot that the polling frequency often jumps beyond the 1000Hz my mouse (Zowie EC2) is configured to run at (I’ve never seen it do this without KVM).
I also noticed that during the “sensitivity drop” the mouse is polling at ~500Hz capped.

I now configured my mouse to run at 500Hz and it works fine.
Not sure why my other machine doesn’t have this issue. Both are win10.

Personally I don’t think I need 1000Hz polling freq. But happy to troubleshoot if anyone has ideas.

PS. I also notice that the KVM has trouble carrying all my USB devices. If all USB devices are “active” at once the KVM often disconnects from my PC for a few seconds. Perhaps Im putting too much data on the wire?

3 Likes

Joris, thanks for the tip.

I’ve been experiencing the same thing. My mouse will slow down as if I lowered the sensitivity for a second or so, then back to normal. This continued to happen every 10-20s. It was driving me crazy while gaming, but it also happen on the Windows desktop. The problem persisted everywhere.

I spent a while testing this with different configurations, viz., USB dongles for keyboard/mouse from the 2-port hub inside my monitor direct to my PC (worked fine), the monitor hub into the KVM (polling issue), dongles direct into the KVM (polling issue), and used different cables for the console to my PC (polling issue). So it would seem to be the KVM.

Now the good news is, the workaround. Changing to 500hz seemed to alleviate the issue. I made the change and played an entire game with no mouse problem. This makes me believe it has something to do with the USB inside the KVM. I’m kind of disappointed to lose half the polling rate on my expensive mouse but, the convenience of switching between my gaming PC and work laptop with my monitor and peripherals is something I just can no longer give up.

No idea on a real “fix” or “solution” other than - live with it. Might require some kind of hardware change or possible firmware? Not sure either of those are even feasible tbh. I do appreciate what we have in this KVM from Level1Techs, but it’s still a bummer from a product at this price point.

After performing all these tests, I seem to be having the occasional black screen now. That is the next thing to try and work out. Loose/bad cable, or something else faulty? Something for me to do this weekend I guess.

Be happy to help diagnose or discuss this further if necessary. Thanks again for your help Joris.

PS: I have the DP 1.4 Dual KVM with a Logitech G903.

-lenderachu

2 Likes

Thanks for the fix!

I set up my KVM (4x dual DP1.4) a few days ago, and noticed the same thing on multiple computers. My Logitech G403 is plugged directly into one of the console HID ports in the KVM, no USB hubs. My mouse would slow down as if the DPI was lowered for a few seconds, then return to normal. Annoying for work, but totally unacceptable while gaming.

So far, reducing the polling rate from 1000Hz down to 500Hz has fixed the issue for an hour or so. Cheers!

1 Like

Has there been any resolution on this topic. Just bought my kvm and it is very disappointing o have this issue.

This is usually caused by computers speaking to the USB peripherals at different polling rates or with different software. If you can normalize the software (I e. Install driver software, same version, on all hosts) then it’s less likely to happen.

It’s not really a KVm thing per se. You can use a usb3 port to do straight passthrough which dis/reconnects when you switch inputs, too.

Thanks for the fix!

I was having an issue with bluetooth 2.4 Glorious mouse and bluetooth 2.4 virtuoso xt headphones not working while both connected to a powered Sabrent USB A 3.0 hub. Changing the polling rate of the mouse to 500 hz seems to have fixed it.

In case anyone else was having this problem, maybe this will help

edit: oops meant to reply to joris
edit 2: nevermind its only intermittently working. But it does work with a USB 2.0 hub

I have the exact same problem with my wireless logitech mouse. Moving the mouse in any game lets the frames drop from 60 to almost freezing the picture completely. I am unable to play anything. Installing logitechs driver software (version 9 or LGHUB) gives me a BSOD and the machine reboots.
Reducing the polling rate to 500MHz does nothing.
Any other ideas?

EDIT: I setup a complete fresh vm and the problems are gone. Seems to be related to some driver problem within the old windows installation. i will report back if i encounter this again.
for now this issue is solved for me !

2 Likes

Have exactly the same thing, question is why do i need 16k dpi mouse and 500$ kvm to lower anything?

You don’t? It’s a software thing as the folks who got the issue resolved reported?

Y, by lowerin the pollin rate :\

I use an mx3s at 1khz which works fine. But that’s across all inputs.

I have a Logitech MX Master 3S, and I have this problem. I looked online to see if there was a way to change the polling rate, which appears to be tied to the fact that it’s wireless, at 90Hz.

This lag happens even when I’m not gaming, and is really frustrating. Only started happening after I starting using the 4port 2-monitor DP 1.4 KVM.

Tried usb3? If you can’t change host settings the USB3 ports are basically straight passthrough instead of hid. Shouldn’t do that. Note that op didn’t change polling rates but instead uninstalled and reinstalled which cleared it up for them …

I’m not using HID at all. You are saying uninstall and reinstall my logitech drivers?

Literally using an MX Master 3 (not s) from this machine right now and it doesnt slow down or do weird stuff.

You know this sounds crazy but it could be rf interference. You got the USB extension cable that came with the kit? If so try the reciver in that …

1 Like

I didn’t get an extension cable in the kit, but I did buy some high quality ones later. All are USB 3.1. One is USB A, the other 2 are USB C (to connect to several macbooks).

I have uninstalled the logitech software and reinstalled it. That didn’t seem to do much.

I think I need to really pay attention to what I’m doing when I see this behavior and see if I can pin point if this is timing, application, system load related, etc.

All I know is that this started happening after installing the KVM.

I am wondering if plugging in the reciever by itself at the end of a USB extension closet to the mouse solves it. The USB3 ports in gernal can cause lots of rf interference

The front of the KVM has both HID and USB 3 ports. I tried connecting the mouse dongle directly to the front USB 3 port, and I saw the same behavior.

not directly into the front of the kvm, at the end of an extension. that puts the receiver farther away from other sources of interference…