resmon-lite

A small, lightweight system-stats app for the Ubuntu taskbar (system tray). Shows CPU %, RAM used/total, and per-GPU utilisation, VRAM, power draw and temperature — colour-coded as values climb.

CPU     12%   56°C
RAM    19.3/ 64.0 GiB
───────────────────
GPU 0 · Radeon AI PRO R9700
       97%   30.5/ 34.2 GiB    66 W   73°C
GPU 1 · AMD Raphael iGPU
        0%    0.0/  0.5 GiB    47 W   57°C
───────────────────
Quit

The tray icon is a tiny level meter — one bar per metric (CPU, RAM, one per GPU) with a dimmed track and a coloured fill from the bottom — that mirrors the same colours, so you can see trouble at a glance without opening the menu.

Status colours

Range	Colour
< 50% utilisation (or < 75 °C)	green
50–74% utilisation (or 75–89 °C)	yellow
≥ 75% utilisation (or ≥ 90 °C)	red

All thresholds and colours are configurable — see below.

Pin to screen

The tray menu has a Pin to screen toggle that opens the same stats as a small always-on-top, borderless, translucent panel you can leave on your desktop:

• Drag it anywhere; the position is remembered across restarts.
• Scroll wheel over the panel adjusts its opacity (the tray menu's opacity radio buttons stay in sync).
• Right-click the panel to unpin it.
• If resmon-lite quits while pinned, it re-pins at the same spot on next start.

Starting opacity, text size and text colour are configurable — see below.

Requirements

• Ubuntu 22.04+ with GNOME (Wayland or X11) — uses the Ayatana AppIndicator, already present on stock Ubuntu (gir1.2-ayatanaappindicator3-0.1).
• Python 3.11+ with PyGObject (python3-gi, standard on Ubuntu).
• AMD GPUs (amdgpu driver). GPU utilisation needs the kernel parameter amdgpu.gpu_busy_percent=1; if it isn't set, the util column shows n/a and everything else still works.
• NVIDIA GPUs need the proprietary driver plus the optional nvidia extra (pip install "resmon-lite[nvidia] @ git+https://github.com/The-Deflection-Engine/resmon-lite.git@v0.2.0"), which pulls in nvidia-ml-py for NVML. Without it, or without the extra installed, NVIDIA GPUs are just skipped — everything else still works.

Only required Python dependency is PyGObject; metrics come straight from /proc, sysfs and (for NVIDIA) NVML, with no subprocesses spawned per poll.

Run

./resmon-lite            # run from this checkout (no install needed)
./resmon-lite --print    # print one reading to stdout and exit

Or install it as a regular command, e.g. straight from GitHub:

pip install --user git+https://github.com/The-Deflection-Engine/resmon-lite.git@v0.2.0
resmon-lite

pip install --user puts the command in ~/.local/bin, which needs to be on your PATH (pip warns if it isn't) — add export PATH="$HOME/.local/bin:$PATH" to your shell rc file if resmon-lite isn't found after installing.

(pipx install git+https://github.com/The-Deflection-Engine/resmon-lite.git@v0.2.0 works the same way, in its own venv.) For hacking on a local checkout: pip install --user -e ..

Autostart with the session

ln -s "$PWD/resmon-lite" ~/.local/bin/resmon-lite        # launcher on PATH
cp resmon-lite.desktop ~/.local/share/applications/
mkdir -p ~/.config/autostart
ln -s "$PWD/resmon-lite.desktop" ~/.config/autostart/

Configuration

Optional file at ~/.config/resmon-lite/config.toml (see config.example.toml). Every key is optional:

Key	Default	Meaning
poll_interval	2.0	seconds between updates
util_warn / util_crit	50 / 75	% thresholds (CPU, GPU, VRAM) for yellow / red
temp_warn / temp_crit	75 / 90	°C thresholds for yellow / red
color_ok / color_warn / color_crit	green/amber/red	hex colours
overlay_opacity	0.7	starting background alpha of the pinned overlay (scroll wheel overrides)
overlay_font_pt	12.0	text size in the pinned overlay, points
overlay_text_color	#ffffff	base text colour of the pinned overlay (hex); status colours still apply to values

Notes & design

• GPU backend: AMD via amdgpu sysfs (/sys/class/drm/cardN/device/…, hwmon for temp/power) and NVIDIA via NVML (optional nvidia-ml-py dependency). Every GPU present is listed automatically, so mixed AMD + NVIDIA systems and new cards "just work". AMD names come from lspci (looked up once at startup, with a small built-in map for very new cards); NVIDIA names come straight from NVML.
• CPU temperature: read from the k10temp / coretemp hwmon chip.
• RAM: MemTotal − MemAvailable from /proc/meminfo.
• Icon: drawn with Cairo to a PNG in ~/.cache/resmon-lite/, rewritten only when values actually change.
• Single instance: resmon-lite owns the D-Bus name org.resmonlite.App for the session; starting a second copy prints a notice and exits. The name is released automatically on crash, so there are no stale lock files.