pcitop is a relatively low-precision, real-time diagnostic utility for Linux that visualizes the PCIe device topology and monitors data throughput across the bus.

• Topology Visualization: Displays a hierarchical tree of PCIe bridges and devices, similar to lspci -t.
• Real-time Throughput: Monitors active transfer rates (MB/s) for:
  • NVIDIA GPUs (integrated via nvidia-smi).
  • Network Interfaces (via sysfs counters).
  • NVMe Storage (via block device statistics).
• Interval Summation: Displays the total amount of data moved during each GUI refresh interval for accurate burst tracking.
• Cumulative Totals: Tracks total RX/TX data since start or last reset.
• Persistence: Save visibility settings (hide/show devices) to pcitop.ini.
• Non-Root Support: Automatically falls back to sysfs to display link speeds and widths when run without sudo.
• Decoupled Architecture: High-frequency background sampling (up to 1ms) with a stable, throttled GUI (1s) to eliminate flickering.

• Not a full logging tool. Some logging info can be added later - but it's not a goal of this tool
• Not working with different internal buses which just looks like PCI for OS - like AMD Infinity Fabric inside of APU

• Show only interesting devices

• libpci-dev
• libncurses5-dev
• cmake
• git

mkdir build
cd build
cmake ..
make

./pcitop

Note: Run with sudo for full access to hardware registers and more detailed link capability information.

MIT License

• This version mostly implemented with Google Antigravity using Gemini 3 Flash and Gemini 3 Pro models with some manual coding/fixing.
• While I implement a few more version of pcitop - by hands and with local models like qwen 3.6 and gemma4 - this version looks more promising and suitable for third-party use.