What is a KVM?

Feb 15, 2026 - 14 min read - 2692 words

I am a programmer, and hardware’s not my strong suit. But I’m still enamoured by all things tech, including hardward. I’ve watched a few videos on KVMs, and I was left feeling like some questions were “unanswered”. So, I turned to ChatGPT to get some answers. Here’s our conversation.

What is a KVM? For example, I’ve heard of the GL.iNet Comet Pro KVM, and I’m wondering what its true usefulness is.

Short answer: A KVM is a device that lets you control a computer’s keyboard, video, and mouse from somewhere else. Models like the GL.iNet Comet Pro are modern “KVM-over-IP” devices—small hardware boxes that let you fully control a PC or server remotely, even if the OS is broken or the machine is rebooting.

What a KVM actually is

KVM stands for Keyboard, Video, Mouse. Traditionally, it was a switch used to control multiple computers from one keyboard/mouse/monitor.

Today, most people mean KVM-over-IP:

Hardware plugs into a computer’s HDMI + USB ports
Sends the video feed over the network
Lets you control keyboard/mouse remotely like you’re physically there
Works even at the BIOS level or when the OS isn’t running (Intel)

That’s the big difference vs tools like Remote Desktop:

Remote Desktop needs the OS and network working
KVM works at the hardware level, even if the machine is crashed or powered off (with accessories)

What the GL.iNet Comet Pro is


GL.iNet Comet Pro Remote KVM — $246.99	GL.iNet Comet PoE Remote KVM — $177.99	Waveshare Luckfox PicoKVM — $97.99	JetKVM IP KVM Remote Controller — $145.00

The Comet Pro is a compact, modern KVM-over-IP box designed for remote control of a single computer.

Typical capabilities:

Remote keyboard/mouse + live video control
BIOS-level access (install OS, troubleshoot boot issues)
4K video passthrough and low-latency streaming
Wi-Fi + Ethernet connectivity
Virtual media (mount ISO files remotely)
Security features like VPN, 2FA, etc. (Medium)

Some versions even support:

Remote power control
Booting machines from fully off states
Touchscreen and onboard storage (GL.iNet)

So… what is it actually useful for?

1) IT / servers (primary use)

This is what KVMs were made for:

Managing servers in a rack or data center
Recovering a machine that won’t boot
Installing OS remotely
BIOS configuration from another city/country

Admins can control machines “as if sitting in front of them.” (Intel)

2) Homelab / tech enthusiasts

Common in:

Home servers
Proxmox / NAS setups
Remote GPU rigs
Network appliances

People use them to avoid needing a monitor plugged into every machine.

3) Remote troubleshooting

Example:

Your PC won’t boot
Windows is corrupted
Network drivers broken

Remote desktop won’t work. A KVM still lets you see the screen and fix it.

4) Remote access without trusting software

Unlike TeamViewer/RDP:

Doesn’t depend on Windows/macOS running
Works even if system is offline or reinstalled
Hardware-level isolation can be more secure

When a KVM is overkill

For many users, it’s unnecessary.

You probably don’t need one if:

You only want remote access to your own PC
You can use Remote Desktop, SSH, Parsec, etc.
You don’t manage servers or headless machines

A KVM is like a “last-resort remote control.”

Real pros vs cons

Pros

Works when OS is dead
BIOS/boot-level control
True “sit-in-front-of-the-computer” remote experience
Great for IT, labs, and critical systems

Cons

Expensive vs software solutions
Adds setup complexity
Overkill for normal home users

Some community feedback also notes firmware maturity and feature gaps can vary by model. (Reddit)

Simple analogy

Remote Desktop = controlling a computer through software
KVM = plugging a long invisible keyboard/monitor cable over the internet

Should you care about the Comet Pro?

It’s valuable if you:

Run a homelab
Maintain multiple machines
Need remote BIOS access
Travel but manage systems

It’s not very useful if you:

Just want to remote into your daily PC
Don’t troubleshoot hardware or OS issues

Quick check: What made you look at the Comet Pro specifically?

Homelab/server curiosity
Remote access to your main PC
IT work
Just exploring networking gear

Your use case determines whether it’s a “game-changer” or a $200 gadget you’ll barely use.

Hm. There’s a lot there to digest.

I am curious about how a KVM is able to access a computer of IP if the computer is turned off. I would assume that you do not mean “the power is turned off”, because that strikes me as needing some physical access. But if power is on and the computer is “shut down”, are you saying a KVM is able to power it on? How does that work? I thought an IP access to a computer is only possible if the computer is already booted.

Great question — and you’re thinking about it the right way. The key is this: a KVM-over-IP doesn’t connect to your computer “through the computer.” It connects to the hardware around it.

So it can still work even when the OS is down or the machine is shut off (but plugged into power).

First distinction: three “off” states

When people say a computer is “off,” they may mean different things:

OS crashed / frozen → power still on
Shut down → power supply still connected, motherboard getting standby power
Unplugged / PSU switch off → truly no power

A KVM works in #1 and #2. It cannot do anything in #3 unless you also use a smart power device.

How a KVM still connects when the computer is “off”

A KVM-over-IP is a separate mini-computer with its own network connection.

It plugs into:

HDMI/DisplayPort (video output)
USB (keyboard + mouse emulation)
sometimes power/reset header pins on the motherboard

It does NOT depend on:

Windows
Linux
network drivers
the PC’s IP address

Instead:

You connect to the KVM’s IP address, not the computer’s.

The KVM:

reads video signal directly from the GPU/motherboard
injects keyboard/mouse input as if physical devices are plugged in

So if the machine powers on, you immediately see BIOS/boot.

“But if it’s shut down, how can it power on?”

This is the interesting part.

Many KVMs support remote power control using one of these methods:

Method 1 — Power button header control (most direct)

Inside your PC case, the power button connects to two pins on the motherboard.

A KVM can:

plug into those same pins
simulate “pressing” the power button electronically

So from the web interface:

click “Power On”
KVM shorts the pins
PC starts

Exactly like pressing the physical button.

Method 2 — Wake-on-LAN (software-assisted)

If enabled in BIOS:

the network card listens for a special packet
receiving it powers the system on

This requires:

motherboard support
NIC power in standby
correct network configuration

Less reliable remotely across the internet.

Method 3 — Smart power strip / PDU

In server setups:

KVM controls a networked power unit
cuts power, restores power → system boots

Used in data centers.

Why video works before the OS loads

The GPU outputs video as soon as the system powers:

BIOS screen
boot menu
disk errors
installer screens

The KVM simply captures that signal like a monitor would.

It doesn’t “log in” to anything.

Why normal remote desktop can’t do this

Because it depends on:

OS running
network stack loaded
remote software active

If Windows fails to boot:

RDP = dead
TeamViewer = dead

KVM = still working.

Important limitation

You were right to question this:

“IP access only works if the computer is already booted.”

That’s true for software remote access.

But KVM is:

hardware-level
parallel to the computer
not inside it

Think of it like:

a robot sitting at your keyboard + monitor, connected to the internet.

Real-world example

Let’s say your home server is in the basement.

You’re traveling.

It:

crashes during a BIOS update
won’t boot

With KVM:

Log into the KVM’s web interface
Click power cycle
Watch BIOS screen
Enter BIOS
Boot recovery USB remotely

Without KVM:

you’re calling someone to press buttons

The one thing KVM cannot do

If:

PSU switch off
power cable unplugged
breaker tripped

Then:

motherboard has no standby power
power button pins do nothing
KVM cannot start the PC

At that point you need:

smart plug
or a human

Why this matters (the “aha” moment)

KVMs exist for one specific nightmare:

A computer that is physically alive but logically inaccessible.

Examples:

bad OS install
kernel panic
boot loop
encrypted disk prompt
BIOS misconfiguration

That’s when they become incredibly valuable.

If you’re evaluating the Comet Pro specifically, the key question is:

What machine would you want to recover remotely?

main PC
home server/NAS
homelab
workstations
something else

That determines whether a KVM is a lifesaver… or just interesting tech.

It sounds like the KVM is something you have to have pugged into the computer you want to connect to, not the computer you are connecting from. Is that correct?

Yes — exactly right.

A KVM (especially KVM-over-IP) is a piece of hardware that sits next to the computer you want to control, not the one you’re controlling from.

Think of the layout like this:

[Your laptop anywhere]
        │
   (internet)
        │
   connects to
        │
[ KVM device ] ── plugged into ── [ Target computer ]
                  HDMI + USB + (maybe power pins)

You never install it on your own laptop. Instead, you install it on the remote/target machine.

Why it works that way

The KVM needs physical access to:

the computer’s video output
the keyboard/mouse inputs
sometimes the power button pins

It basically pretends to be:

a monitor
a keyboard
a mouse

And then streams all of that over the network to you.

So:

you connect to the KVM’s IP address
not the PC’s IP address

Example setup (home use)

Say you have a server in a closet.

You plug the KVM into that server:

HDMI → server GPU
USB → server USB port
Ethernet/Wi-Fi → your network
optional → motherboard power pins

Then from anywhere:

open a browser
connect to the KVM
you now see the server screen and control it

Your own laptop could be:

Windows
Mac
Linux
tablet
even another continent

It doesn’t matter.

Simple analogy

A KVM is like leaving:

a webcam pointed at your monitor
and a robot pressing your keyboard

You control the robot remotely.

The computer you’re using to connect is just a viewer/controller — it doesn’t need special hardware.

When people get confused

They assume it’s like:

Remote Desktop
TeamViewer
SSH

Those run on the target computer.

KVM runs beside the target computer.

That’s why it still works when:

the OS is dead
networking is broken
the machine hasn’t booted yet

Typical places you’ll see them

Servers in racks
Home NAS/homelabs
Offices managing multiple PCs
IT support setups
Edge devices (remote locations)

Less common for:

everyday personal desktops

If you’re picturing real-world use, the deciding question is:

Do you have (or plan to have) a computer that you might need to access when you physically can’t reach it?

That’s the scenario where a KVM goes from “neat gadget” to “invaluable tool.”

So, if I wanted to have KVM access to a couple of NASes and a couple of home computers, I would need one for each box? That seems somewhat limiting. What about if I wanted a single KVM for all my computers (desktop, NAS, everything) in my home? What does “connected to the computer” mean? Is it just the network cable connection, or am I missing something here?

You’re zeroing in on the exact trade-off with KVMs — and yes, your instinct is right.

A typical KVM-over-IP device is physically attached to one computer at a time. So if you want hardware-level remote control of 4 machines, the simplest setup is 4 KVM units (one per box).

That’s because “connected to the computer” means physical cables, not just network.

What “connected to the computer” actually means

It’s not just Ethernet.

A KVM usually plugs into the target machine using:

HDMI / DisplayPort → to capture video output
USB → to emulate keyboard + mouse
(optional) motherboard power/reset pins → to turn it on/off
its own Ethernet/Wi-Fi → so you can reach the KVM remotely

So the KVM is literally acting like:

the monitor
the keyboard
the mouse
and sometimes the power button

That requires direct wiring.

Why one KVM ≠ multiple machines (by default)

A small device like the Comet Pro only has:

one HDMI input
one USB control link

So it can only “sit in front of” one computer at a time.

It’s not like a router or switch that multiple devices can share.

But there are ways to control multiple machines with one KVM

Option 1 — Traditional KVM switch + IP KVM

You combine two devices:

Physical KVM switch (multi-computer selector)
IP KVM plugged into that switch

You ─ internet ─ IP KVM ─ KVM switch ─ PC 1
                                   ─ PC 2
                                   ─ NAS
                                   ─ Server

You:

connect to the IP KVM
then switch which computer you’re viewing

Downside:

more wiring
potential compatibility quirks
switching not always seamless

Option 2 — Enterprise / rack KVM systems

Data centers do this.

One rack unit:

supports 8–32 machines
each server gets a small adapter cable
all feed into one central IP KVM

But:

expensive
designed for rack servers
overkill for most homes

Option 3 — Only use KVM where it truly matters

This is what most homelab users do.

Example:

NAS → KVM attached (critical system)
Hypervisor server → KVM attached
Desktop PCs → software remote access only

Because desktops:

usually have working OS + network
don’t need BIOS-level remote control often

Important NAS detail

Many NAS devices don’t even need a KVM.

Examples:

Synology
QNAP
Unraid boxes

They already run:

web management
SSH
remote console

You only need KVM if:

the NAS OS fails
bootloader issues
hardware troubleshooting

Visual: single vs multi-machine setup

Key mindset shift

A KVM is not a network access tool.

It’s a physical presence replacement tool.

You deploy it where you’d otherwise need to:

walk over
plug in a monitor
press keys
hit the power button

The practical home setup most people land on

After experimenting, many end up with:

1–2 KVMs total, not one per device.

They choose:

the server that runs everything
the machine in a closet
the box that’s hardest to physically access

Everything else:

RDP
SSH
web UI
Tailscale / VPN

The real decision question

Before buying multiple KVMs, ask:

For each machine:

Would I ever need BIOS access remotely?
Could I tolerate being locked out until I get home?
Does it run headless in a closet/rack?
Is it “mission critical”?

If the answer isn’t strongly “yes,” software remote access is usually enough.

If you tell me what machines you’re thinking about (desktop, NAS models, servers, etc.), I can map out:

where KVM actually makes sense
where it doesn’t
and what a realistic home setup would look like without overspending.