The helper is optional. Most users should start with just the Stream Deck plugin and decide later. macOS users do not need the helper at all — it is Windows-only.
Without the helper, the plugin can already show CPU, memory, disk and network usage, and on NVIDIA cards: GPU usage, temperature, power, and voltage. That covers most Stream Deck keys people set up first.
Install the helper if you want
Depending on your hardware, the helper can also expose:
- CPU package temperature and power
- motherboard sensors, fan speed, voltage readings
- detailed GPU sensors, especially on non-NVIDIA cards
- other low-level data exposed by LibreHardwareMonitor
The exact list depends on your machine — different CPUs, GPUs, motherboards, and sensor chips expose different data, and not every machine reports every sensor. You can install the helper later; you do not need to decide during your first setup.
Why a driver is involved
Windows does not expose these deeper sensors through standard user-mode APIs. Reading them requires a kernel driver. Many Windows system tools use drivers for similar reasons, including antivirus tools, game anti-cheat systems, RGB and fan-control utilities, and hardware-monitoring apps.
Installing any driver is still something to do deliberately. The rest of this page explains what gets installed and what each part does.
What gets installed
The helper sensor stack has two pieces:
- the ShoMetrics Windows helper, a user-mode local service
- the third-party PawnIO driver, used by LibreHardwareMonitor inside the helper for low-level sensor access
ShoMetrics does not require you to install LibreHardwareMonitor separately — the helper uses the library directly.
PawnIO is installed by you, not by the helper. You download and install PawnIO yourself from pawnio.eu; the helper does not install or bundle it. This is by design of PawnIO’s authors — PawnIO is meant to be installed explicitly by the user, not silently by other apps.
If you do not install PawnIO, the helper still runs, but sensors that need driver access will be unavailable.
What PawnIO is
PawnIO is a signed Windows kernel driver used by hardware tooling to reach sensors that standard user-mode APIs cannot. Rather than exposing raw I/O to user-mode callers, it runs small signed bytecode modules that each perform one task — read this sensor, query that chip — which keeps the attack surface narrower than older “give-me-MSR-access” drivers.
PawnIO is third-party software. If you later remove ShoMetrics and no other app on your PC uses PawnIO, you can uninstall it from Windows Settings → Installed apps.
Some strict anti-cheat systems, such as FACEIT, have previously misreported PawnIO. According to the PawnIO author, the PawnIO.Setup issue should be fixed as of 2.1.0. Install PawnIO only from the official site, and use PawnIO 2.1.0 or newer.
If you have read complaints about LHM’s old WinRing0 driver
Older LibreHardwareMonitor versions shipped a driver called WinRing0 that
had known security concerns (CVE-2020-14979) and is what some users have
flagged on reviews of other LHM-based tools. ShoMetrics has never used
WinRing0 — the helper has been built on PawnIO from the first release.
If you do not want the driver
Do not install PawnIO. The Stream Deck plugin still works without the helper, and the helper still works without PawnIO — you just will not see sensors that need driver access.
Before installing
- download the helper from the official ShoMetrics download page or release, and download PawnIO only from pawnio.eu
- be ready to approve administrator prompts for both installers
- note that uninstalling ShoMetrics does not automatically uninstall PawnIO
Ready to install? See How do I install the Windows helper?.