+1000 points for the PiKVM V4 Plus. We (Revise Robotics - a YC company!) refurbish laptops with robots and AI - as part of this, we (or rather, the AI) send(s) keyboard commands in software to the computers we're refurbishing.

How/why? The AI needs to navigate the BIOS among other tasks - so we need a KVM to send arrow down and enter, roughly speaking.

We were a GL.iNet KVM shop until we ran into a nasty issue with a specific ThinkPad - the GL.iNet would send an incorrect USB 0 byte which most laptops ignored, except this ThinkPad which was freaked out by it / beeped / wouldn't accept any key command.

I couldn't let this problem go, so I got a low level USB debugger [0] (which I extremely recommend) and wire-debugged the USB signal, A/B comparing the GL.iNet and the PiKVM. The PiKVM was doing things properly (usb-wise), so we swapped all (~10) of our KVMs for it.

I also remember that the GL.iNet was stranger/more difficult to customize (it's just running pikvm the software but doesn't let you customize it as much). The GL offers a nicer UI, but it doesn't matter that much (we drive it via API) and we're happy to support the actual PiKVM authors/company. It's a fantastic product. Not cheap, but truly truly great.

P.S. If someone from GL wants to reach out, I can offer you a lot of low-level debugging info -- fixing this issue would be great.

[0] https://greatscottgadgets.com/cynthion/

The JetKVM picture is aggravating to look at. It shows IPv4 address in large print and the IPv6 address in small print. That’s fine, but the IPv6 address is truncated with an ellipsis. How is that useful? A truncated IP address doesn’t work. Do the developers expect autocomplete for IP addresses? And the IPv6 address is a ULA, so it could have been much shorter.

Not affiliated but I had good experience with GL.inet’s comet line [1]. They have one on kickstarter that’s the size of a google cast puck that uses purely usb-C. Though all my KVM do not have internet access (blocked at my gateway). I can only access it via tailscale externally.

[1] https://www.gl-inet.com/products/gl-rm1/

Okay, there were two things that bothered me with these KVM switches: the power adapters are massive so there's too many cables, and the cables don't go always in the same side of the thing. Your post covers both and I'm thrilled. The final thing I recognize is a bit of a nice to have but the only thing that I want to rack that doesn't have a BMC is my Mac Mini which I've hesitated to put in the Sonnet RackMac and run because I don't know how to KVM power it on/off. My cabinet is an hour away from me and the Mac Mini runs the family AI agent so I need it to be available all the time. So far, it hasn't ever needed any attention (it comes back on after power outages at home) but I'd prefer to be able to turn it on/off remotely ideally.

Do you know which one of these works well with that?

Hey Jeff, I did some research on the jetkvm after reading this as I was very impressed but wanted full scale hdmi + Poe and was going to pull the trigger on the clone you mentioned later, ArkKVM but felt like I’d rather support the main project if I could…

What I found seems to indicate that Jet fixed those two issues in a hardware revision but it’s really difficult to distinguish the new on from the old as they’ve seemingly kept the same name and not added a v2 or something like that to the naming. One of their vendors has a Poe va non poe sku, the other has a an emmc vs tf card sku. All seemingly without a name distinguishing them.

There’s also just chaos on Amazon as they are being sold in at least 4 separate listings with no name distinguishing which model is which, non of them mention poe and all claim full size hdmi.

In any case I thought you should know that your write up is out of date here but you probably need to do some digging to figure it out.

It will never make sense to me why KVMs are such a hard problem to solve. It seems like something we should have a good answer for by now but we still really just don't without dropping hundreds of dollars, and even then it still feels like a crap shoot.

Neat, someone mentioned these when I proposed a ludicrous anti-fingerprinting strategy https://news.ycombinator.com/item?id=44549352

Jeff Geerling rocks

I have a CSE847 and HP DL380 G10 that have gone down for me due to power outages. Many of these look complex, and I basically just need remote power-on/toggle capability. Should I be looking at something else?

I have a mild distrust of some of the cheap IP KVMs. I don't think vendors are malicious, but I don't expect they get it right every time either.

Admittedly, I haven't looked at any open-sourced firmwares either which could have improved things.

I have found the Sispeed USB KVM very useful, the convenience is well worth the $50 it cost me. The UX isn't great but you don't really need it to be. It works (most of the time) via WebUSB for the keyboard mouse.

Glad I bought a JetKVM, it's been great (other than the HDMI adapter, lol)

I deploy pikvm and I have been mostly happy. The tinypilot has a better feel to it. Something feels more polished.

Radxa also released their ipkvm product last week called radxa linkr. It costs by $55

How's the video quality/latency on all of these? RDP or parsec are probably the gold standard, but I doubt cheap arm SOCs can implement either properly.

I'm running a PiKVM DIY on a pi02w. Adequate, but I'd like more functionality and performance.

I bought a SiPeed NanoKVM. It caught fire 15 minutes after being plugged in. Despite providing pictures of the charred PCB, they insisted I ship it back, costing me €20, and then tried 3 times during the transit to get AliExpress to void my return as fraudulent. I eventually provided proof of signed delivery to their people on the last possible day of my final appeal, and AliExpress ruled in my favor, refunding my purchase price but not the return shipping cost. Better some money back than none at all!

Maybe just buy the JetKVM. It looks nice!

Another vote for JetKVM. Tailscale support is great. I'm glad to see audio is in the works because a Mac mini screaming from separate room during a remote session is disappointing.