EDIT: see last pic at bottom for the updated diagram
Hi everyone, i just purchased a level1techs KVM switch as i was told this was the best one to get. I dont know much about KVM’s so please forgive me. I am not sure if i have all the proper cables to get it working (just ordered it, in transit). I was hoping someone can weigh in with any missing pieces i might need. Here is my setup:
i have a dell 5570 laptop and a desktop with 3 x 27" PG279Q /144hz monitors i want to share between this desktop and the laptop.
I purchased the 2 computer / 3 monitor KVM from level1tech’s
The laptop has 3 x USB-C outputs, i also have the docking station k17a that has 1 x HDMI and 1 x mini-display port on it.
My desktop has an RTX3090 with 3 x displayPorts out going to the monitor.
I guess my question is, i assume i just plug in the USB-C into the KVM from the laptop, then plug in 1 DP from my desktop into KVM, then 3 DP’s out to the monitor ? I am just not certain if i can go USB-C direct from laptop to KVM ? or do i need an adapter ? or maybe the HDMI from the laptop dock is better ?
The kvm is one input to one output for displays. You want to run 3 displays? Each display has a dedicated connection back to the device powering the display.
So your laptop will need to route some of the displays via an active HDMI to dp adapter or a thunderbolt dock. The thunderbolt dock reduces the amount of bandwidth available for displays sharing that connection because it’s shared but for not the highest res and refresh monitors it’s probably okay.
Your desktop PC will need 3 dp connections to the kvm for 3 dp monitors if that’s what you want to do.
From this diagram of my env, does this look accurate on how to cable this ? I kinda get the PC end as its 3 display outs i have already, but i wasn’t sure about the laptop. I wasn’t sure if i could go directly from maybe a USB-C out of the laptop directly to the KVM with maybe a USB-C to DP cable ? or do i have to use the thunderbolt dock with HDMI out to HDMI-to-DP adapter ? I am not sure of any pros or cons of each if i can do that. There is also a mini displayport on the dock as well, not sure if that changes anything.
USBC to dp should work fine for the laptop. Some thunderbolt docks have dual dp and if you don’t care about lower Mac refresh you can do active HDMI to dp plus dual USBC to dp or dual dp via dock just fine
This is a windows laptop by the way, i just noticed these are thunderbolt 4 ports on the laptop on one side x 2 and 1 x usb 3.2 Gen2 Type-C DP on the other side… not sure if it makes a difference or not.
would i still be able to use 3 monitors ? (144p) with the laptop with ‘some’ connection ? just not sure what is the best one to use ? dock with HDMI and adapter ? thunderbolt direct to KVM x1 or x2 ??
I dont think my dock will accommodate my setup. I also have another dock: Dell WD22TB4 dock that has 4 ports on it ( 2 x DP 1.4, 1 x HDMI v2.0, and 1 x USB-C 3.2 Gen 2/DP 1.4). I think based on what you are saying, i need 1:1 ratio of ports on both laptop and desktop to use all 3 monitors work properly ? Based on my new dock, it is cabled something like the following ?
I finally got the KVM and hooked everything up, for the most part, switching is working good, even 2 DP’s from the Dell Dock are using 2 monitors just fine.
I have found a weird problem with keyboards. Luckily enough i have 4 keyboards here to test with. When i plug in my main driver Corsair K100, it lights, but no key inputs other than the hotkeys work just fine to switch computers. I plugged in my Apex Pro and it doesn’t light or work at all. frustratingly, i plugged in my 2 cheapest keyboards (HyperX Elite and some no name brand 20$ keyboard) and they work just fine… Any ideas why the 2 higher end keyboards are not working ?
For the Corsair, Apex Pro and HyperX keyboards, i plug the 2 USB cables coming out of each keyboard into 2 of the HID ports on the back of the KVM, then plug the mouse into the front of the KVM.
I found a solution to the Corsair K100… had to put it on a powered USB hub and plug it into the back usb3 port, seems to work ok. I haven’t tried the APEX Pro, but may try it later. I assume the KVM ports do not provide enough power for some of the peripherals …
I had issues with USB coming from a TB dock once, was Gov laptop. Does work with the tech refreshed one my wife has now tho so not sure wtf they did to that last one
One thing about the hid ports is thst they are grouped togetber internally so one device can cause problems for all the other hid devices. And you might have to reboot the kvm.
Focusrite stuff also via usb3 is good. Dont think steelseries follows the hid standard
I wanted to upload this final solution i setup this week as working just in case it helps someone else… i was lost when i started this journey, so maybe this can assist someone that was in my shoes a few weeks back.
My goal was to be able to flip from work laptop to desktop and also bring over my keyboard, mouse and desktop (jabra 510) between 2 zoom calls (zoom or teams joined on each machine)… this works flawlessly.
The only issue i had was getting the keyboard working (fixed from above) and the jabra 510 going missing mysteriously without any interaction. I managed to get it back in sync and so far so good. Just to point out, you can run 1 thunderbolt cable to a dock and run 3 monitors off the dock directly… no issues running at 144p at 120 Hz on Monitor 1 and Monitor 2 and 3 @ 60 hz refresh… maybe this is dock related ?? monitors spanning (3 x PG279Q). works great
That is incredible! Wow! ThTs actually pretty great.
Any mac people reading this, dont get any ideas. This person has a nice laptop that likely does display stream compression. Or possibly something in the dock. Usually its merely okay, and not for high refresh displays on the laptop in high refresh mode.
Sorry, must have re-edited it before you posted above. I thought about this, and didn’t really check my laptop refresh, only my desktop, but of course that will have 165hz refresh as its 3090 direct connect x 3. I am just reading about the laptop refresh discrepancies now. they look like this, but still acceptable:
monitor 1: 144p @ 60 Hz
monitor 2: 144p @ 120Hz (main one i set)
monitor 3: 144p @ 60Hz
looks like i can only set one to 120 Hz, still researching why this is though
so i just moved the USB-C to DP direct to laptop port like you originally suggested and its goes full 165 Hz for that specific connection. For the other 2 still connected to the dock, they allow both 120 Hz… so i guess an educated guess is that its 60Hz x 4 port dock, or it must combine some how depending on the # of monitors you plugin (up to 4). With 1 going to thunderbolt port in dock and 2 x DP from dock i get:
monitor 1: 144p @ 120 Hz
monitor 2: 144p @ 120Hz
monitor 3: 144p @ 165Hz ← bypass dock and plug to laptop direct
but i just set monitor 3 to 120Hz to match, i found 60Hz just fine for desktop work as well.
All in all, you are 100% correct if you want to achieve full refresh rates, the dock will limit you, but thinking about this, its a work laptop, i really dont care about high refresh rates on it, only my gaming machine, so this setup is more than acceptable.
Here is what i am sticking with as it gives me 120Hz 144p across 3 monitors on my work laptop and full 144p @ 165Hz across 3 monitors on gaming rig… phew ! thank you Wendell
