I am having some issues with my new 2PC 2 monitor 1.4 KVM. I am not getting my refresh rates to work above 60hz but I just bought some FIBBR cables that were recommended in other threads and they should show up today.
I originally had a USB HUB with everything plugged in through my dock to my monitor KVM (M32U) but I was having so many issues with the KVM in the monitor that I opted to switch to an actual KVM. I plugged my HUB into one of the USB 3 Gen 2 ports and they get power, but not seen in the OS.
I then unplugged my camera and plugged it directly into the KVM non-HID ports and then it is seen in the OS (lsusb on Linux) but doesn’t register with any software. My Mic which is a Logitech Yeti Blue has power as the hub is powered but the OS never sees it either.
I then plugged them directly into the Doc and they work and the laptop and they work. The issue is I would like them both to be on the KVM but neither work when connected to the KVM either through USB Hub or directly into the ports.
Any suggestions to fix this or any suggestions on good USB hubs that will work on the KVM?
did you plug the devices into the hid side initially? the kvm remembers that… when devices show up and are squirrely you may need to power off the kvm for a minute or so, then power it back on. Use only the blue ports for what you’re attempting.
What’s the usb3 hub in question? for the first power cycle I might start w/o the hub and try the devices in the blue usb3 ports first as they should work there after the kvm power cycle.
Its likely the 60hz thing is very likely cabling. Everyone always thinks their ‘vesa certified’ cables aren’t that bad (but they are)
@wendell, I will try to power cycle it. I am now having an issue with my keyboard not working at my drive decrypt when booting Linux but it works once getting to the login screen. It used to work, but when I was messing around with the ports to see if any of them worked it stopped, so the power cycle may fix that also.
The HUB that I am using is “Powered USB Hub RSHTECH Aluminum 4-port USB 3.0 Hub with 5V/2A Power Supply and Individual On/Off Switch It is just a standard 4 port powered 3.1 hub”. The forums will not allow me to link it but I purchased it from Amazon .co.uk I bought a 12 port but I don’t think it will be used as I don’t need that many ports with the KVM.
Update, I switched the Display port cables from my Desktop to the KVM and the KVM to the monitors to be using the FIBBR cables. I am still unable to get above 60hz. As soon as I set it to 120 the screen goes black and won’t come back on and it says no signal.
EDIT____ Ignore The below power cycling my Dock got the monitors working again.
With the FIBBR cables from the KVM to the monitors, and my laptop uses the Kingston TB4 Dock (USB C to DP) I am not getting no signal to either monitor.
I power cycled the KVM and still getting nothing.
2nd EDIT____
Pulled the power from the KVM inserted the Webcam and mic - reapplied the power to the KVM and I am getting the same results. Used the USB 3.2 ports and not the HID. The keyboard still doesn’t work until after getting to the login screen.
Are you using usb3 cables from each pc to the kvm? Something about your setup is not making sense. The usb3 ports are a basic usb hub type function. I have never encountered a situation where the keyboard did not work on a usb3 port until the os loads.
Can you take a pic of the ends of your usb cables?
What monitor is in the mix here? If its the gigabyte m32u thats a great monitor. Fibbr cables on both aides of the kvm? Doing 120hz or 144? Id start with 120 but 144 is worth trying even if 120 doesnt work because 144 uses dsc.
I am using 10ft Fasgear USB C 10Gbps cables from both PC’s. I have the keyboard plugged into one of the HID ports. The keyboard I use is the ZSA Moonlander, so it uses a usb c to usb a adapter to connect (provided by ZSA).
This is my current setup which uses the 2 PC 2 Display 10Gbit KVM. Desktop to KVM (PC1):
Using two FIBBR Flash 144 2m cables using the Source side into the GPU (3080 TI), and the Display side into the KVM. The above 10 ft Fasgear USB c to c cable from the Mobo to the USB c input on the KVM. Then an audio cable from the audio out of the mobo into the KVM.
Laptop Razer Blade Pro with 3070 (PC2) only needs 60hz:
TB3 from the laptop using TB4 cable plugged into a Kingston TB4 dock. From the dock, I am using two of the TB type C connectors with 2m Uni DP 1.4 type c to DP cables into the KVM. Audio cable from dock to KVM, and the thrid TB type C connection from the dock to the KVM usb c for data.
Then from the KVM I am using two more of the 2m FIBBER flash 144 cables using the Souce side from the KVM and the Display side plugged into each of my M32U monitors. My audio jack from my speakers plugged into the audio in on the KVM. For USB, I have my mouse plugged into the rear HID port (when looking at the back it is the one by itself on cluster of 3 ports), then my keyboard plugged into the HID (top left of the cluster of three (when its plugged into the bottom left it wasn’t working at all).
I am about to try moving the type c data cable from the dock to the extra type c port on my laptop (most the usb issues are with the laptop and the display issues are with the desktop). I will report back if that fixes the mic and webcam while having them plugged into the USB 3.2 ports.
Right now, the desktop was able to up it to 98hz on both displays sometimes. If I go above it sometimes doesn’t like going back down to 98 or 60 and to fix it, I need to remove a DP cable and reconnect to get the signal back again. Pushing to 144 resulted in no image also but I originally wasn’t trying my luck because I didn’t know it used different technologies and the dock is advertised as 120hz.
I also tried turning off G-Sync in nvidia control panel and then upping to 144 and 120 and it did not work.
Edit___
Tested the USB C from laptop to KVM bypassing the dock for data only and having the mic and webcam plugged into the USB 3.2 and neither are registered on the laptop which runs Linux, however, they both work flawlessly when bypassing the KVM and plugged directly into the laptop.
Whats the output of lsusb and dmesg when bypassing the dock on linux when no usb device is working?
For the zsa moonlander in a hid port try disabling nkey rollover.
What firmware version is on the m32u? I have an m32u and it works at 120/144 here without issue but there was a firmware update for it. I need to also check if there is an eco mode or power save thst can be disabled from the osd.
If you have an a to c cable that might be worth trying from the desktop as not all usbc controllers are created equal. Genrrally the type a ports work better on desktop motherboards even for 10gbps.
@wendell, I had a 2nd edit but got distracted and missed hitting the update button. From the laptop I looked up the laptop and it appears that both usb C ports on the laptop are connected although only one is TB3. I switched it to a c to a like you mentioned and now both devices are registered in lsusb and applications are able to see and use them. I might hit the bandwidth limit on that port maybe.
As far as the monitors, I updated them to F10 firmware shortly after I bought them. I looked and see that F11 is out and updated, but that did not appear to fix my issue either. The update put me into Eco picture mode again but I already went back and updated it to Custom1 and made my alterations again. I do not see anything else about power save. I have the monitors set to not turn off and the AMD free sync enabled even though it always says off on both monitors.
Thats very interesting. You might try to power cycle the kbm one more time and retest with the fibr cables. If thst still doesnt worrk email me wendell at level1techs.com and i will setup an rma to test on our crazy cable tester and our gb m32u.
Maybe worth doing ddu and fresh gpu driver install too.
I already tried to do a reinstall of the drivers, but I will try a full removal with reboot and reinstall. I will also try plugging the FIBBR cables from the PC directly into the monitors to see if the GPU is still capable of it for some reason. I will report back after.
Update. I did some looking while trying to get DDU to work. I saw that Gigabyte issued a GPU bios update for the Aorus 3080Ti Master which said it fixed Display Port Compatibility issues. Got to looking to find my bios version and saw that I was only running on PCIe 8x. So did some digging and moved a shared M2 to restore x16 bandwidth. Seems like that didn’t actually change anything though as each monitor is running with 4 lanes at an 8.1 Gbps bandwidth (Max and Current at 98hz).
Then I got DDU working in safe mode (my safe mode is broken and I have no taskbar so it wasn’t easy) and then rebooted and reinstalled the newest drivers from NVIDIA. Was able to get both monitors to 144hz when not connected to the KVM. Connected back to the KVM and all appeared to be working. Went down stairs to get some lunch and came back up to randomly each monitor losing signal and coming back on until I dropped the refresh rate back to 98hz.
I looked at power saving modes in the Mobo bios, and inside Windows and did not see anything. Right now I am also getting very small white specs appearing all around one of my monitors even at 98hz and it’s very quick and looks kinda like static.
I then saw that my GPU BIOS was the correct F2 bios and I tried to reinstall to see if that would do anything, but apparently, you can’t reinstall only upgrade as it keeps telling me that the update file is the wrong bios. I really don’t know what it could be at this point.
Wendell let me RMA my KVM, sent me back a new one with a video showing each port running 4K/120 and 4K/144. After a lot of stuffing around it turned out to be an issue with the Aorus Master 3080Ti. Mine will not go above 4K60 with my Samsung Neo G8 and even 4K60 with 10bit HDR is an issue and all this with FIBBR cables.
It seems to be a DP signal strength issue as using 1m Club3D cables and a Cable Matters DP powered repeater I can get it to work through the KVM, but it is still not happy, flickering, going black for a few seconds, etc. All detailed in my thread.
I switched out the AORUS Master 3080Ti for a AORUS Master 6900XT and the issues went away, rock solid 4K/120/240 with HDR enabled.
Interestingly my second PC with the 3060 (also a Gigabyte card) sometimes flickers now and the monitors go blank until I cycle KVM inputs. Maybe it is also an nVidia issue too.
In the end I have the AORUS Master 3080Ti in my system only when I need CUDA or Ray Tracing performance and I connect it to the Neo G8 over HDMI and just accept that I need to flick the monitor input as well as the KVM input. All other times I keep the AORUS Master 6900XT in my system now. It has been a much more stable card.
You have a Gigabyte card and monitor so maybe Gigabyte will help you, but they refused to help me and refused to replace my card. Since you are having a similiar issue, I suspect if they did replace my card, I’d just have the same issue.
Maybe @wendell can get a hold of a AORUS Master 3080Ti somehow and using his testing equipment, figure out what the card is doing. I don’t have the gear to do that unfortunately.
Hey @Matt84, I actually was doing some digging after @wendell sent me an RMA and I came across your post and saw that you were having the same issue. I didn’t want to go out and get a new card, but I figured I didn’t want to go the RTX way on the 40 series with all the melting connectors. I saw a few YouTubers review the 7900 XTX cards and all had nothing but good things to say. So I was able to get my hands on a Sapphire 7900 XTX card, and while the FIBBR cables are kinda wide for it, I was able to finagle them to both pluged in without breaking anything. Then after using DDU to remove the NVIDIA drivers and then installing the AMD drivers, I was able to easily push 4k/144hz. I apologized to Wendell in the email for ever thinking it was the KVM, and I am glad I found your post, as the last thing I wanted to do was send off the KVM since I am in the UK. Mailing it here took almost 30 days (I didn’t choose the priority option, and in hind site, I probably should have).
My plan for my Aorus Master card is probably to either wait and get a NUC that it will fit in and put it downstairs as a dedicated VR gaming PC or add it to my home server box and do PCI passthrough to a VM that I can use to run certain games and then I could finally get rid of Windows on my desktop! I would use it for password cracking, but my employer won’t let me use personal equipment for client tests, which is understandable.
Hey @ZerkerEOD the KVM does have an affect. It doesn’t boost the signal but it does introduce some losses. The AORUS Master 3080Ti works fine connected to my Neo G8 at 4K120/240Hz with 2m Club3D cables. It really doesn’t like FIBBR DP cables though. Put the KVM into the mix and it doesn’t work. Using a CableMatters DP repeater did get 4K60 with HDR working but not reliably in game. From memory 4K120/240 would light up with the repeater but blank out every 30 seconds or so and completely unstable in game. This is what leads me to believe the AORUS Master 3080ti has a very weak or is very sensitive when it comes to DP signal. I did think it just hated the Neo G8 but your experience disproves that.
As far as getting the KVM into @wendell it may still be worth it. My old KVM did have an issue where my Mac Mini M1 would not allow me to use greater than 60Hz or HDR. The returned KVM that @wendell tweaked works with it no problem now. Not all KVM PC inputs are equal. Even on my fixed KVM, the top input for PC4 will not drive above 4K 60Hz 8bit SDR for any of my computers with the Neo G8. If I tried 4K 120 8bit SDR or 4K 60 HDR, the Neo G8 will report no signal. No biggie though as i just switched DP cables so my 4K 60 SDR screen is used for that input. @wendell did show that PC4 input working with a 4K LG 144Hz monitor no problem though so it comes down to your own configuration too; GPU, KVM, and monitor.
One thing I learned is 4K120 is right on the edge of what DP 1.4 can do and DSC introduces other issues too. That will teach us for buying tech that is right on the bleeding edge.