Code · Open-source tool / native Windows app
ResMon
A deliberately lightweight Windows 11 resource monitor: a single self-contained C++ executable that shows CPU, GPU, RAM, temperatures, network and disk I/O in a compact desktop widget.
- Role
- Solo developer
- Platform
- Windows 11 x64
- Workflow
- AI-assisted (Claude)
- License
- MIT
Overview
Many system monitors weigh more than the load they watch. ResMon goes the other way: no installer, no runtime, nothing to set up. Unzip it and run it.
What it shows
- CPU, GPU and RAM load, plus network and disk I/O. Every row can be switched on or off.
- CPU temperature on Intel and AMD Zen processors, read through the signed PawnIO driver, with a Windows thermal-zone fallback.
- NVIDIA GPU temperature through NVML, loaded on demand from the installed display driver, without CUDA or nvidia-smi.
Right-click options cover always-on-top, an update rate of 1, 2 or 5 seconds, dark and light themes, opacity and starting with Windows.
Why it stays lightweight
- No Electron, .NET, Qt or browser engine: the UI draws directly with Direct2D and DirectWrite
- Expensive probes run less often: CPU clocks roughly every 10 seconds, temperatures less often than load
- Counters for hidden rows are not collected at all, and NVML is only loaded when temperatures are shown
- Value easing runs on a short-lived timer that stops once the numbers settle
The sensor components needed for the driver-based CPU temperature readings are embedded at build time, and the driver is only installed on request, through the normal Windows UAC prompt.