atop

A real-time system performance monitor for macOS, written in Go. Inspired by asitop — no sudo required.

Features

• CPU — total usage bar, per-core grid; Apple Silicon shows P-core vs E-core averages
• GPU — device, renderer, and tiler utilization via ioreg (works on Apple Silicon)
• Memory — RAM and swap usage with sizes
• Disk I/O — read/write bytes per second across all disks
• Network — upload/download bytes per second
• Load averages — 1 / 5 / 15 minute

Requirements

• macOS (Apple Silicon or Intel)
• Go 1.21+

Install

git clone https://github.com/anitabendelja/atop
cd atop
go build -o atop .

Or run directly:

go run .

Usage

atop [flags]

Flags:
  -i, --interval duration   refresh interval (default 1s)
  -h, --help                help

Examples

atop              # 1 second refresh
atop -i 500ms     # 500 ms refresh
atop -i 2s        # 2 second refresh

Press q or Ctrl+C to quit.

How it works

Metric	Source
CPU	gopsutil (host_processor_info)
GPU	ioreg -r -c IOAccelerator
Memory	gopsutil (vm_statistics64)
Disk I/O	gopsutil (IOKit)
Network	gopsutil (net_io_counters)
Load	sysctl vm.loadavg

Built with

• cobra — CLI
• bubbletea — TUI framework
• lipgloss — terminal styling
• gopsutil — system metrics