The KVM switch isn't compatible with HDMI-DP or USB-C to USB audio devices.
The KVM switch isn't compatible with HDMI-DP or USB-C to USB audio devices.
I purchased a KVM switch available at the link provided. It features USB-A 3.0 ports and DP 1.4 connectivity, which should accommodate my 1440p 144Hz monitor—though my laptop runs at 60Hz, and I upgraded to 1440p as well to prevent scaling problems during setup. The switch includes USB-A ports and only DP for video output. My desktop has USB-A ports, whereas my laptop only supports USB-C and HDMI for video. I noticed this issue in a discussion here. The KVM should connect to my desktop using both USB-A and DP cables. However, it won’t link to my laptop with a DP adapter to an HDMI-to-DP converter. Similarly, it won’t connect to my laptop via a USB-A to USB-C adapter. But with a USB-C hub equipped with USB-A ports, it will work. I’ve included a detailed diagram to clarify this.
I realized there’s an identical HDMI version available, priced $20 higher. I opted for the DP model, assuming a compatible HDMI-to-DP adapter would function. I’m considering a dedicated active HDMI to DP adapter (like the one listed) instead of returning my current unit for the extra $20.
My questions: Do adapters need to be active since the KVM can’t switch between HDMI and DP, or USB-A and USB-C? Would something like this for HDMI to DP work?
And why do some adapters claim to be active, yet none seem to function properly? I’m frustrated with the hassle. I’d appreciate any guidance, especially regarding software solutions like Stardock’s Multiplicity. The lag is too severe for smooth video calls and screen sharing. Thank you for your help!
Consider reaching out to the KVM vendor to understand why the HDMI to DP converter isn't compatible with that specific KVM. Both HDMI and DP signals are quite similar, so a passive adapter should suffice for conversion. Additionally, the USB-C to USB-A connection functions actively as it operates through a basic USB hub. You might want to verify if your HMDI to DP adapter is directional—if it is, it would only work in one direction and not reverse.
It looks like the cable you thought was HDMI to DP is actually DP to HDMI. I’ll just buy a basic HDMI to DP cable and check. The display issue isn’t too big—my main problem is with the whole setup: laptop (USB-C) → dock (USB-C) → dock (USB-A) → KVM (USB-A). On my desktop it works perfectly, but on the laptop it seems keyboards or headsets only work sometimes. Mouse and webcam seem fine. Could it be related to power consumption or the conversion process? Edit: after testing, it seems I can get at most two out of three devices working—headset, mouse, or keyboard when plugged in. The webcam works regardless and doesn’t seem affected by being plugged in.
Yes, the item description mentions uni-direction only if your USB-C port is a USB2 port. Otherwise, it should support all three devices with sufficient power. It's tricky since laptops vary and USB hubs aren't standardized. Does your hub offer an external power input? Regarding the signal, it should allow connecting three devices simultaneously without issues. However, your device might have an unlisted restriction, making it uncertain. I suggest testing another hub to confirm. Have a great day!
The hub details mention USB-A 2.0 ports and a USB-C connector that only supports PD 100W with specific compatibility standards. It seems the limitation might stem from USB-A 2.0 not being able to deliver sufficient power for multiple devices, especially when they draw a lot of current like a headset, mouse, and keyboard. The Dell Precision 5680 you’re using has two Thunderbolt 4 ports and one USB-C port, but the dock you’re connecting to only has a Thunderbolt 4 port. Trying to power three devices through that setup still results in insufficient charging for all of them.
I still struggle to get all devices functioning properly, especially with the USB-A to USB-C adapter I discovered. It only lets me connect two of the three devices—Mouse, Keyboard, or Headset—never all three. The problem seems to lie with the USB-A 3.0 to USB-C/Thunderbolt 4 conversion. To address this, I ordered a KVM Switch with HDMI 2.0, since both my monitor and laptop only support that standard. This should eliminate the need for conversions and save me about $15. Regarding the USB-C issue, I have a backup mouse that works, though its comfort isn’t ideal. I could use it as a temporary fix by connecting one mouse to each device depending on the task, or even swap it out if needed.
Microsoft offers a complimentary application named Mouse Without Borders, enabling you to manage several devices using a single mouse. When operating systems vary—such as MacOS, Linux, or Windows—these paid options become available.
The computer I own needs the mouse plugged in all the time, correct? I prefer turning off my desktop when not using it and putting my laptop into sleep mode otherwise. It seems the setup is focused on having several screens and just dragging the mouse between them—my setup only has one monitor connected to both my desktop and laptop. Thanks for the advice!
This situation is a bit confusing. The KVM port uses DP, while the laptop connects via HDMI. They’d require an HDMI to DP adapter instead of a direct DP-to-HDMI setup. Although the signals look alike, they’re distinct enough that passive conversion isn’t possible without special equipment—typically a DP++ port. In @Infiniti’s configuration, they specifically need an HDMI to DP adapter that stays active. This device manages the signal transformation from HDMI to DP. If it were a DP-to-HDMI setup with a DP++ port, the adapter would handle conversion internally. On the other hand, using bi-directional cables is uncommon, costly, and always active. I’m here to clarify this point, as it’s something I’ve explained repeatedly over the years.