[Official] Level1Techs KVM FAQ -- Ultimate Guide & Help!

Use fibbr brand fiber optic dp cables Then theres no real length limit

How do you expect the KVMs to hold up to RDNA3 and DP2.1?

I’m waiting for the 4x1 DP1.4 L1KVM to re-stock, and I’ve got a CalDigit USB-C SOHO dock on the way to hook up an M1 MacBook alongside Linux and Windows (VFIO) machines.

QUESTION: If I set all of my sources to output audio via DisplayPort, will I get audio output on the console DisplayPort?

I links for the moshi usb c cables are broken. What is the link for this (just to be sure i get the right one):

If you want to connect a MAC to your DisplayPort KVM, use this!

Amazon.com: Moshi USB C to DisplayPort Cable 1.5m/5ft, Support [email protected] Hz, 4K HDR, VESA Certified, Aluminum Housing, Thunderbolt 3 Compatible (Ensure Monitors Accept DisplayPort Signal) : Electronics

It says DP1.3 on it though and I’m needing a DP1.4 cable for 4k144 HDR, anyone know if these moshi cables work with that? I’m having a hard time getting my Mac to reliably reconnect to that monitor, so far my work and personal PC do fine, but the Mac isn’t happy at all, wondering if I need an EDID repeater but the only one that claims to work with DP1.4 is Amazon.com: 【Che-Ker】 DP 1.4 Emulator ([email protected]) : Electronics but it’s new so no reviews, plus probably sketch af, plus also says it may work abnormally with a USB C to DP adapter which the Mac would require…

Sorry for the delayed reply, here is the link directly to Moshi’s website :slight_smile: I have updated the post link as well:

Any idea when the Dual Monitor 4 Computer and the DP Repeater will be in stock? Looking to pick one and two/four/five up respectively.

Also wanted to get an opinion on a setup as well. I have 3 systems I need to hook up for this, the only relevant screens going into it are a UWQHD with DP and HDMI, and a FHD with HDMI only (I plan to replace this eventually). I also have a QHD and matching FHD that go to a gaming PC and are always on that system. A reasonable gaming PC on arch, a w10 Dell laptop with a Dell WD19TB dock (2 DP, 1 HDMI), and an m1 macbook with a USB C hub (HDMI only). I absolutely hate the macbook but it’s what I’m forced to use. The pc and dell did fine when it was just the 2 of them and I was using DP and HDMI to one screen with a usb switch. Adding in the macbook made this more annoying than I’d like and a newly added cheap kvm works so far, but the macbook makes my life hell since it doesn’t like when I switch in and out of it with the KVM.
The question is how best to manage this?

Plan so far is

  • Gaming PC - DP1 & DP 2 → L1 KVM. Out to UWQHD and a DP->HDMI for FHD monitor.
  • Dell + Dock - Same as above but with the repeaters in the middle of the inputs.
  • Macbook M1 + Hub - Add 2 Moshi cables → repeaters → L1 KVM

I’d take any help on that one though. I was never expecting to run 3 systems in this particular setup, but now that I am, it’s worth the money to make it work so I can not be stuck on a tiny macbook screen or dealing with it’s shoddy multi monitor support.

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@wendell

I noticed when I plug in the KVM to a Mac, there is a “keyboard” device called “Virtual HID”. Is there any documentation on what this device does?

thats the hid endpoint for the kvm where it emulates a keyboard but can sniff hotkeys for hotkey pressing. this thread has the hotkeys that work assuming your keyboard is hid

Got excited seeing the DP repeater in stock email, “Add to Cart” followed by “Item is out of stock”

Then I noticed the Dual Monitor 4 Computer isn’t listed anymore. Is this gone for good @wendell ?

no, we are updating the dual monitor 4 pc to have a 10gb option

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Thanks, @wendell I finally caved and purchased a fibbr cable. I went from a maximum length of: TB3 dock - 6.56’ club3d dp1.4 → KVM - 6.56’ club3d dp1.4 → [email protected] monitor ~ 13.12’ total to now: TB3 dock - 3.28’ club3d dp1.4 → KVM - 6.56’ fibbr → [email protected] monitor ~ 3.28’ total copper and the difference is night-and-day. I have zero flickering issues across three different computers. I had random issues before where the refresh rate would change (probably due to a bandwidth negotiation issue) and that doesn’t seem to be happening. I’ve spent so much money on cables to dial everything in. The price we pay for productivity perfection!

2 Likes

Apologies if I missed the answer in a post.

I have two 27" 2k monitors - Future may hold one larger 4K and one of these 2k monitors. Though this is not my question.

I have a work Dell Latitude 5431 (aside from the bios/12 gen issues) it has a thunder bolt dock.

Looking at 1.4 Display Port KVM Switch - Dual Monitor - Two Computer

The other system is a desktop pc, video editing, gaming, test lab.

Question one is should I be looking at something that the Dell can “dock” too or is the two monitor - two system the right choice and still use the Dell Dock?

Question two, would that dock being in there cause issues. As noted it is Dumb device but looking to get 2k from the dell dock to both monitors.

Again apologies, and Thank you.

Blah blah blah, TL;DR at bottom

I’ve been using the 4PC/2display 1.4 KVM a while and after adding chokes to all the video cables it mostly works how I’d like it to. It works 100% of the time going to my desktop, my M1 mac mini seems to hate it, but I think I need a HDMI to DP converter to use the HDMI port on the back since the mac seems to hate not having the HDMI in use.

My real issue is with my work laptop. I have an ASUS ROG PG32UQX for my main display with 2 older dell 4k ISP monitors on each side, one of which is on the KVM and the other I switch manually. The laptop can’t power the ASUS at full 144Hz even when directly connected so I settle for 120, but I can’t use the DP ports on the laptop dock to run it as the dock doesn’t have enough bandwidth to push it to 120Hz with HDR anyway and I need both ports for the 2 Dell monitors anyway, so I’m forced to connect the ASUS via a usb C to DP 1.4 cable to the KVM

This DOES work and IS stable… eventually. I don’t see random dropouts once I get it working changing to the work laptop via the KVM is spotty at best. Usually, the ASUS will just go blank, and I have to bring up settings on one of the side monitors and change HDR settings or refresh rate a few times or switch to the unused PC port and back until the ASUS decides it wants to start working again. The cable I use is a Cable Matters USB C to DP 1.4 cable (choked at the DP end), which I know isn’t the recommended Moshi cable, however my question here is the Moshi claims to be a DP 1.3 cable supporting 4k60 (and I REALLY like 4k120 HDR, esp for console connections because you can see stuff flying by a lot more smoothly), so is the Moshi still better and still supports 1.4 despite saying it doesn’t? I’d love for this to work 100% of the time with both work laptop and personal desktop.

TL;DR: The Moshi USB C to DP cable claims to be DP 1.3 only supporting 4k60, but I need USB C to DP 1.4 to support 4k120 w/ HDR.

Also question on chokes, should both ends be choked? does the distance from the end of the cable matter much? I seem to get better results on my Cable Matters USB C to DP 1.4 cable if I just choke the DP end, but maybe I was choking the USB C end too close to the connector? should it be a few inches back? As I understand, chokes increase overall cable impedance and filters out high frequency noise, which for an analog signal reduces signal noise and for digital makes the cable seem worse when handshaking so the systems setup a stronger signal between the two, or something like that.

Laptop

I actually think our USB Centralizer would fix the issue with your laptop:

It is coming to the L1Store soon!


MAC

MACs tend to have EDID issues, so you might also want to look into our DP Repeater + HDMI Splitter.

From the website description:

As a “phantom” monitor with the Level1 KVM. This would sit between a display port PC and a display port input port on the KVM and would provide a “phantom” signal to your PC and your PC never knows you have switched displays. In so doing, it also cleans up and repeats the signal which can be problematic on some devices like Apple Mac that use low-power display port. This is the confirmed fix for the 2013 trashcan mac pro if you want to use it with the Level1 KVM.

Let me know if you have any questions!

That’s the exact opposite problem that I have, I have USB-C and need to go to DP 1.4, and real DP 1.4 because it’s a 4k144Hz monitor, tho even directly connected the laptop doesn’t seem to like to go above 120.

Same issue as above, the monitor needs a full DP 1.4 signal and also has variable sync so an EDID repeater, esp a DP 1.3 one, won’t really work.

The only option i kniw of. Especially with macs, is a thunderbolt dock with full size dp out. A la caldigit ts3+ or better.

Be aware apple doesnt qc quality of the dp output as i can see huge snr variance from mac to mac of the dame model and batch with the 15k$ analysis machine… sad days

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Hello!

Long time user of the L1 KVM (PAAG-E3122B) and today I just attempted to connect a DAS Keyboard 6 Professional to the HID ports and did not get any connectivity. I can connect it to the front USB port and it works.

I had read about disabling NKRO to possibly fix this but it appears DAS hasn’t updated their KMs to reflect any functionality on their site for this specific KB.

Update: I contacted DAS’ support and you aren’t able to disable NKRO on this keyboard specifically.

Thank you!

if you can flash to qmk that might be a viable option. qmk is prettymuch the best firmware for custom/exotic/nice keyboards and the sooner everyone moves that way, the less we’ll all suffer :slight_smile: