Gjallarhorn

Gjallarhorn is a modern, lightweight, and cross-platform system resource monitor written in Rust using the Slint UI toolkit. It provides real-time visualization of your system's performance metrics with a sleek and customizable interface.

Features

• Real-Time Monitoring:

  • CPU: Visualizes per-core usage with support for 60-second history.
  • Memory (RAM): Tracks total system memory usage.
  • GPU: Monitors NVIDIA GPU Compute and Memory usage (via nvml-wrapper).
  • Network: Displays real-time upload/download traffic for all active network interfaces.

• Customizable UI:

  • Dark Mode: Toggle between Light and Dark themes.
  • Color Customization: Fully distinct colors for CPU, RAM, GPU, and Network charts.
  • CPU Color Modes: Choose between a "Uniform" single color for all cores or distinct "Random/Hue-based" per-core colors.
  • Persistent Settings: Your preferences (colors, theme, mode) are saved automatically and restored on startup.

• Modern Design:

  • Responsive layout with Drop Shadows and rounded corners.
  • Smooth animations for buttons and menu transitions.
  • Tabbed interface for organized data viewing.

Installation

Prerequisites

• Rust Toolchain: Ensure you have Rust installed (cargo). Install Rust
• System Dependencies:
  • Fontconfig (for Linux font handling)
  • NVIDIA Drivers (optional, for GPU stats)

Install from Source

git clone https://github.com/arunkumar-mourougappane/gjallarhorn-rs.git
cd gjallarhorn-rs
cargo install --path .

This will compile and install the gjallarhorn binary to ~/.cargo/bin/ (make sure this is in your PATH).

Install from crates.io

Once published:

cargo install gjallarhorn

Building from Source (Development)

git clone https://github.com/arunkumar-mourougappane/gjallarhorn-rs.git
cd gjallarhorn-rs
cargo run --release

Usage

1. Launch: Run gjallarhorn from your terminal (if installed), or use cargo run during development.
2. Navigation: Use the Sidebar to select "Usage" (Monitoring View). The top tabs allow switching between CPU, RAM, GPU, and Network details.
3. Preferences:
   • Click File > Preferences to open the settings dialog.
   • Dark Mode: Switch themes.
   • CPU Colors: Toggle "Uniform Color" to use a single color for all cores, or disable it to use persistent random colors for each core.
   • Other Colors: Pick custom colors for RAM, GPU, and Network charts.
4. Quit: Select File > Quit to exit.

Configuration

Settings are stored in your system's standard configuration directory (e.g., ~/.config/gjallarhorn/config.json on Linux) and persist across sessions.

Performance

For the smoothest experience, always compile and run Gjallarhorn in Release mode. Debug builds include extensive runtime checks that can significantly slow down the SVG chart generation (parsing ~1000 data points per second).

cargo run --release

or build an optimized binary:

cargo build --release
./target/release/gjallarhorn

Tech Stack

• Language: Rust
• UI Framework: Slint
• System Info: sysinfo
• GPU Info: nvml-wrapper
• Network Info: default-net
• Serialization: serde & serde_json