Fixed: Level1 KVM (DP 1.4) has video artifacts

I just recently purchased the Level1 Dual Monitor DP 1.4 KVM switch. It seems to have introduced very noticeable visual artifacts.

I purchased the following cables which seem to work flawlessly directly between my computer and monitors, but once the switch is introduced I see the artifacts. I can’t seem to include links since this is a new account but if you search amazon for the following they should show up:

Cable Matters 8K DisplayPort to DisplayPort Cable (DisplayPort 1.4 Cable) with 8K 60Hz Video Resolution and HDR Support - 6 Feet

I ordered monoprice cables that come on the 30th though. Maybe they will help.

I’ve set my refresh rate to 60hz.

I also see the artifacts on the bios startup animation as well.

Here is a link to a video of the issue.

Updated your account so you can do the video/links to your post. the KVM doesn’t really have any displayport “smarts” so something is happening to cause the computer to negotiate a lower bit rate (possibly 6 bit color or something like that?)

Cable matters is usually pretty good but you might have got some fake ones if you ordered off amazon. Wouldn’t be the first time it happened to me… even specifically with cable matters.

The other thing to keep in mind is that even though each cable works independently, from the vantage point of the computer, the display is twice as far away as it is with the kvm vs without. the KVM doesn’t really pickup and reshape the signal or anything like that so it’s like as if you have two cables butted end to end. Sure either can work independently but is the cable SNR good enough that the loss of two cables + connectors it still works? If it really does adhere to DP spec then yes, but that isn’t always the case.

You could also try a shorter cable between the KVM and the display as it sounds like there is 12 total feet between the display and KVM.

Thanks for the recommendations. I’ll go ahead and order some shorter 3 ft cables as well and let you know how it goes!

I don’t have that KVM but had plenty shitty “premium” (DisplayPort) cables.

Can recommend StarTech cables for DisplayPort and USB 5/10 Gbps stuff, never had a single issue, even when having to run them directly next to a 230 V 50 Hz AC power line.

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Thanks! I’ll look into them as well :slight_smile:

aBav.Normie-Pleb. Thanks for your comment about the 230V! It was interference from the power cable!

I had a bunch of cable management where the display port cables were running beside power cables. I moved the cables away from the power cables and it works perfectly now!


Glad to hear that!

It’s generally recommended to not run data lines next to power cables but especially in home environments that’s easier said than done.

I just wanna have fiber cables for everything except power :upside_down_face:


Am curious, can the L1 KVM be operated with optical DisplayPort cables?

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