How to Check CPU Usage on Linux

High CPU usage can slow down your server. Here's how to monitor and diagnose it.

Real-Time Monitoring

top

Press 1 to see per-core usage. Press P to sort by CPU. Press q to quit.

Snapshot

mpstat 1 5

Shows CPU stats every 1 second, 5 times. Install with apt install sysstat.

Find CPU-Hungry Processes

ps aux --sort=-%cpu | head -20

Load Average

uptime

Load averages show system load over 1, 5, and 15 minutes. On a single-core system, a load of 1.0 means 100% utilization. On a 4-core system, 4.0 is 100%.