I’ve been thinking about what your issue could be. @wendell any idea?
Hi all - having some trouble picking out cables. I have the correct display port cables. I purchased the 10g 3-monitor, 2 -computer kvm switch.
3 monitor display port → 3 display port console connections
3 display port cables from PC1 → computer 1 GTX 1070
3 display port cables from PC2 → computer 2 GTX 3080TI
I also need to plug in keyboard and mouse via USB to the KVM switch. I have those connected.
I assume I need 2 USB-C cables then from PC1/PC2 USB-C to each of my computers. I have seen the recommended cables but they are very short and I need longer cables, ideally 6+ feet.
I need:
USB-C → USB-A (computer 1 only has USB-A inputs)
USB-C → USB-C
Am I understanding this right?
Any links you might have to known working cables that are 6+ feet?
I’m happy to report that I’m finally up and running with my very own 4x1 L1T KVM and can answer my own question: YES! There’s no DAC in the KVM itself but you can plug your speakers into the monitor and the KVM will pass audio through from the DisplayPort inputs to the DisplayPort output.
However, there are some caveats:
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Audio from our ASi MacBooks is garbled, I believe due to CalDigit SOHO USB-C Hub that we’re using for DP1.4 output. Others have reported similar issues with this dock/hub, which is too bad because it’s otherwise perfect.ETA: Installing the “USB Hub Support” driver from CalDigit seems to have fixed this issue.Spoke too soon, LOL. Switching away from the MacBook and back again causes the audio to stop working completely (until and un- and re-plug). - I cannot for the life of me get DisplayPort audio output working on my Radeon Pro W6400 in Ubuntu. I’ve tried adding amdgpu.audio=1 amdgpu.dc=1 to the command line and that didn’t help. I’ve also installed the “official” drivers with no change; unfortunately I’m on Ubuntu 22.10 so the “pro” drivers aren’t supported. I might try to see if I can get the installer working anyway. ETA: Yeah, that’s a no-go.
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Just wanted to say I ordered the USB-C and DisplayPort cables from the Level1Tech’s store for my v1 USB-C KVM and it has removed all my intermittent issues!
- My 1440p monitor runs at 144hz again without display artifacts on my Windows PC w/ RTX 2070.
- I don’t have to unplug/replug the DisplayPort cable to get my Linux laptop to display to the monitor when switching from the PC.
- Both the laptop and PC properly handshake with the monitor over 99hz when switching between the two without rebooting anything in the chain.
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Laptop properly displays to the monitor when waking from sleep.This appears to still be happening, less frequently though.
Brilliant products! Shipped super quick too!
Edit: Here’s the current layout
Windows PC: RTX 2070 → L1T 100cm USB-C → v1 USB-C KVM → L1T 120cm DP → Monitor
Linux Laptop: Thunderbolt 4 → OWC Thunderbolt Cable¹ → OWC Thunderbolt Hub → 20cm USB-C ² → v1 USB-C KVM → L1T 120cm DP → Monitor
¹Cable came with the OWC Thunderbolt Hub
²Cable came with this USB-C Hub from Uni.
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Glad that fixed your issue! Let us know if you experience any other weirdness 
Disabling NKRO fixes the caps lock issue with my Keychron Q6. Pro-tip: don’t try putting the keyboard into DFU mode when it’s connected to the KVM!
Here’s my cheat sheet for getting this done under Linux. Follow at your own risk. Please note that the process is different for non-Keychron keyboards.
python3 -m pip install --user qmk
git clone https://github.com/Keychron/qmk_firmware.git
cd qmk_firmware
qmk setup # install build dependencies
# extra udev rules so linux can find the keyboard in dfu mode
sudo cp util/udev/50-qmk.rules /etc/udev/rules.d/
# choose the correct keyboard; iso has a funny enter key; encoder
# means it has a knob
KEEB=q6/ansi_encoder
# edit rules.mk and set NKRO_ENABLE = no
vi keyboards/keychron/$KEEB/rules.mk
# make the firmware with the stock keymap and via support
make keychron/$KEEB:keychron
# flash it, but make sure to unplug it from the kvm first and plug it
# directly in the system!
# it will keep retrying, so you can kick it off, put the keyboard into
# DFU mode, and it'll flash straight away
make keychron/$KEEB:keychron:flash
Cheers!
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Ah, thank you for the help and feedback!
Hi, I have few questions:
- Is there a roadmap in the works for a 2 monitor USB-C KVM?
- The spec breakdown shows 10Gbps USB interface (CAAB-E3112). The link, however, only states 5Gbps. Should I assume that it’s the former?
2a) If it’s 10gbps, will there be an issue trying to connect to a 2019 MBP to a 4k 120hz (ASUS PG42UQ)?
Hi thank you for your question!
The USB-C variants of our DisplayPort KVMs are all 10Gbps. The CAAB-E3112 is special in that it is data & display in 1 cable. If you use the USB toggle switch that you’re referencing from the store post, the USB 3.0 port to the right will be 5Gbps. The USB-C connection itself is 10Gbps.
4K 120Hz is fine with the CAAB-3112B so long as you have proper cabling
Awesome.
I have another question. This is directed more towards Wendell if he has knowledge on it.
I came across a very unique adapter in the chinese market but I could no longer find it. It’s a USB-C to either DP/HDMI with 2 USB type A (I assume it’s 3.0) attach to it. Would he happen to know anything about it? I was hoping to find that particular product again as this might solve my problem in a cost friendly manner (not requiring to get a new GPU with USB-C output for my PC) and attaching it to the Level1techs USB-C KVM.
It’s not awesome though. I don’t think that answer means what you think . Stated another way… One cable only has so much bandwidth. If you want to use all your bandwidth for USB you ain’t gonna be running 4k/120 on the display side.
USBC+pd kvm is inferior to the dp1.4+USB kvm. It’s basic physics. Two cables is more bandwidth than one.
The store has a signal combiner that combines usb and displayport into USBc. But you are going to lose some bandwidth doing that . . . USBC is quite slow even at it’s max speed vs a separate dp cable and a USB cable.
I understand.
If it’s running to a hub likely consisting of Keychron Q1, USB DAC, USB Microphone and wireless mouse, would it still be able to retain 4k/120? I don’t expect to plug thumbdrives to it.
The idea is to minimise cabling as much as possible as my MBP only has 2 usb-c slot. I don’t mind not getting full 4k120 on my MBP as its mainly for work, but anything would be better than what I’m currently able to drive (4k/30) via HDMI
Dumb scenario time.
2 Monitors (High Resolution\Refresh Rate), 2 PC’s (Gaming + Dev) & a Laptop (only 1 PC needs high refresh, rest can be lower). Hoping to do USB C for the laptop with PD.
I’m guessing my best scenario is the DP 1.4 2 Monitor / 4 PC & use a separate dock for the laptop? Or am I missing that the USBC combiner would work in this scenario (it looked more like the other way)
Don’t have any plans for a combo USB-C/DP KVM by any chance :P?
Cheers
I have the “1.4 Display Port KVM Switch - Dual Monitor - Four Computer”. I’ve been having issues with the spacebar on my Logitech G512 issuing double spaces when I press the button once. I’ve also encountered a similar issue with the G502 Hero mouse. I have tried them on different computers with out the KVM and have not experienced any issues. Has anyone else encountered issues like this?
Try a usb3 port instead of a hid port. Seen that kinda thing from wildly mismatched USB polling rate and mismatched Logitech software versions on the different PCs. Sometimes also the host USB port matters more than you’d think, too.
Has anyone experienced an issue where USB inputs (KB + Mouse) seem to randomly cut out for 4-6s? I’m not sure it’s KVM related, but curious if anyone has seen this behavior before.
My system is a very new X670 gigabyte board running pop os.
What keyboard & mouse do you have? Also, does changing port type (USB-HID to USB 3.0) help?
Is it possible to use a headset with microphone on the 2-monitor/4-DP KVM? I have a 3-ring audio cable between the PC and the KVM, however, I can’t get the microphone to work.
Hi Folks, dumbest of dumb questions here…
The USB C variants basically are intended for gizmos that basically only have usb video, right? I mean, keyboards and mice don’t use that much bandwidth…and I can’t see plugging a usb drive into a kvm…just want to be sure before I go on a hunt for cash 
Haha xD no dumb questions! You’re on the right track, but let me explain the differences.
The L1Techs CAAB-3112 is data & video in 1 USB-C cable. So yes this is handy for MACs that only have USB-C ports for instance or graphics cards with USB-C output. If you do not have USB-C video you’re probably better off with a display port KVM instead.
The normal display port 1.4 KVMs come in a 5 gigabit (USB-B) or a 10 gigabit (USB-C) variant. The connections will still be display port for video, but you will have a separate USB cable running to your inputs. The USB-C model is handy for high speed/high bandwidth peripherals like external SSDs or high-polling-rate USB-HID devices.
Hope that helps!