Samsung Odyssey G9 + DisplayPort 1.4 + Nvidia RTX 40 issue

KVM Model

DisplayPort 1.4 (4-ports)

USB Interface (5-gigabit or 10-gigbit):



I recently upgraded to a Samsung Odyssey G9 (the G95SC specifically 5120x1440 240Hz). I had been using a L1Tech DisplayPort 1.4 KVM (4-port model) for over a year with the old monitor without issue.

I have 3 computers attached:
1 - Desktop Nvidia RTX 4070
2 - Desktop with Nvidia RTX 4080
3 - Mini PC with AMD Radeon 780M GPU

I can’t get any video output from the 2 Nvidia setups. I’ve used Club 3d DP2.1 copper cables, Fibbr DP2.1 copper cables, and GeoHN.G fiber optic cables. I think they are defaulting to 240Hz. I tried connecting a 2nd monitor and manually the Samsung to 120Hz, but I sill cannot get any video output. The monitor believes there is nothing connected to the DisplayPort when either machine is selected.

The mini pc with the AMD 780M defaults to 120Hz and runs fine.

All machines run fine when directly connected to the monitor using either DisplayPort or HDMI.

Do you have any ideas on what could be occurring? I’ve been trying various cables for days without success. Are there any cables or adapters that have been know to work with RTC 40 cards?

Other Notes:

I tested another KVM from ConnectPro. It was able to display video from the Nvidia setups at 240Hz but that KVM has some other issues. It also fails to display anything at 120Hz.

Id start with club3d cables on either side of the kvm and make sure the total length of wire on both sides of the kvm combined is less than 10 feet.

You can also email me to setup a mail in for deeper diagnostics, generally the g9 is fine.

Make aure the g9 firmware is fully up to date. Sometimes that display is weird and it does help if you unplug it from power for a minute or two to really clear it

Fiber cables are also ok but they have a directionality and if you go fiber do fiber on both sides of the kvm

You can check out a my guide here:

I was mixing with fiber and copper with fiber going into the KVM and copper going into the monitor. I’ll test it with an all fiber setup. Thanks Wendell!

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I think my unit might actually be problematic. I did a firmware update of the monitor and also tried some more cables - all without success. I finally picked up a Ugreen KVM to test with and it surprisingly worked and delivered stable video at 240Hz using the fiber optic cables.

I originally purchased the unit I was using from ebay due to them being out of stock at the time so there’s no way to know what sort of history it has had prior to me receiving it.

I’m going to buy new unit from Level1Techs. I believe it will work given how much success was reported by other users and I really prefer your KVMs over everything else I’ve used in the past.


The new KVM is working well. Interestingly I still had some random artifacts appearing when using the fiber optic cable. However using Club 3D DP 2.1 cables produced resulted in perfect image quality with no issues. Club3D for the win! You guys really do make an awesome product.

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