Choosing a screen for the second PC
Five ways to see the second PC: a portable monitor, a spare monitor, a KVM switch, a phone or tablet running a web radar, or headless remote desktop. It also covers what each costs in practice.
Short answer
The second PC needs a display, chosen by how you will read data during a match rather than by panel quality. A small portable monitor, a spare monitor, a KVM switch, a phone running a web radar or headless remote desktop all work.
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What do you need the screen for?
The second PC's screen does two unrelated jobs, and people buy the wrong hardware when they treat them as one. The first job is administration, such as installing drivers, running a read test or reading an error message. That happens rarely and any screen can do it, including one you borrow for an afternoon. The second job is reading a radar during a match, which depends on glance distance and position rather than resolution. Decide which of these jobs you need before you spend anything, because for administration alone the answer is often no monitor at all.
Which screen option suits your setup?
The options are ordered roughly by how often each one is the right answer for a first build. Every row treats the overlay path, whether a fuser or a capture card, as a separate decision.
| Option | How it works | Strengths | Costs you | Best when |
|---|---|---|---|---|
| Small portable monitor | A 10 to 16 inch panel fed by HDMI or USB-C from the second PC, on a stand beside the main monitor | Always on, no switching, good glance distance, genuinely cheap | Desk space, one more cable, and a panel you will not use for anything else | Radar-led play where you want the map permanently in view |
| Spare monitor | Any monitor you already own on a second input or a second arm | Free if it exists, large enough for administration and radar at once | Real desk space, and it is usually too large for a comfortable glance | You already have one and the desk can take it |
| KVM switch | One monitor, keyboard and mouse shared between both machines, switched by a button | No extra panel, one clean desk, full-size view of whichever machine you switch to | You cannot see both machines at once, so it is useless during a match | Administration and setup work, not in-match reading |
| Phone or tablet as a web radar | The second PC serves a radar over the local network and the phone views it in a browser | No new hardware, a screen you can position anywhere, works over Wi-Fi | Requires a network link and radar software that serves a web view; adds a little latency | You want a map without a monitor, and the software supports it |
| Headless with remote desktop | No display attached; you connect in from the main PC or another device when needed | Zero desk footprint, nothing to buy, fine for a machine you rarely touch | No in-match view at all, and a machine with no display can be awkward to recover when networking breaks | Overlay goes to the main monitor via a fuser, and the second PC is pure infrastructure |
The options can be combined: a common mature setup runs headless or uses a KVM for administration, and adds either a fuser overlay or a phone radar for in-match reading.
Why a portable monitor is the usual first choice
Most first builds end up with a portable monitor, because the radar stays visible without any switching, at a glance distance you can adjust by moving the stand. Choose one for its inputs and stand quality rather than its panel specifications. Before you order, check what the second PC actually outputs, since HDMI, DisplayPort and USB-C with DisplayPort alt mode are not interchangeable. An adapter in that path is one more thing that produces a black screen at a bad moment.
Tip
Can a phone or tablet be the radar screen?
If your software serves a radar as a web page, a phone on a stand is an excellent screen. You already own it, it sits wherever you want it, and it needs no video cable. You need two things: a network path between the phone and the second PC, and software that actually offers a web view. Traffic stays on your own network, but expect slightly more latency than with a wired panel. That is acceptable for a map, though not for anything time-critical.
Warning
Can the second PC run without a monitor?
A second PC with no monitor is a reasonable end state, and remote desktop from your main machine is enough for administration. Plan for one failure case, though: if the network configuration is the thing that breaks, you have no way in. Keep a cheap HDMI cable and a spare input on some monitor available, or keep the option of a portable panel. Every experienced builder has been locked out of a headless box at some point.
What to check before you buy a screen
- You know which video outputs the second PC actually has, from the specification and not from a photograph
- You have decided whether you need an in-match view or only administration access
- If you need an in-match view, you have picked one route: a panel beside the monitor, a phone radar or a fuser overlay on the main screen
- You have measured the desk space the panel and its stand will occupy
- You have a fallback way into the machine if you are going headless
Display questions
Does the second PC need a monitor plugged in to boot?
Usually not, although some machines behave differently when no display is detected and a few refuse to initialise graphics at all. If you go headless and something seems wrong, attach a display once to confirm that the machine is otherwise healthy.
Is a KVM switch worth it?
For setup and administration on a tidy desk, yes. For in-match use, no, because you can only see one machine at a time, which defeats the purpose of a second screen.
Can I use my TV as the second screen?
It works, but glance distance and input lag on smart TVs are practical problems, and both are worse than with a small panel next to the monitor.
What resolution does a radar need?
Very little, because physical size and position matter far more than pixel count. A 1280 by 800 panel at the right height reads better than a 4K panel behind you.
If I have a fuser, do I need a second screen at all?
Not for in-match reading, since the overlay lands on your main monitor. You still want some way to administer the machine, and headless remote desktop or a KVM covers that.
Sources
No outside source covers this; it describes the screen setups that the team and its customers ended up using.
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