atop vs iotop

atop is a free, GPL-licensed performance monitor for Linux. It uses a full-screen ASCII interface to report system and process activity at regular intervals. System-level views cover CPU, memory, swap, disk, and network activity. Process and thread views include CPU use, memory growth, disk use, and other statistics, including consumption by processes that finish during the interval. atop can save compressed raw counters for longer-term analysis, preserving daily logs for 28 days by default. The atopsar command turns those logs into system activity reports. It also reports CPU, memory, disk I/O utilization, and pressure for cgroup v2. An optional netatop kernel module adds per-process and per-thread TCP and UDP packet counts and bandwidth statistics. Displays can use bar graphs or detailed text, with columns adjusting to terminal width. Downloads list source and x86_64 RPM packages for version 2.13.0.

iotop is a free Linux program that identifies processes generating high input/output activity and lists them by I/O usage. The display can show accumulated I/O or bandwidth, with optional read, write, swap-in and I/O-percentage columns. Monitoring can target selected process IDs or users, or show processes and threads across the machine. Interactive and batch modes support iteration counts, configurable delays and timestamps in batch output. Command-line filters narrow processes by TID or command using a regular expression. Installation guidance covers Debian-derived distributions, Fedora, CentOS/RHEL, Void, Arch and Alpine Linux; source builds use make after development dependencies are installed. The project is GPL-2.0+ licensed, but installation and use require root access. Version 1.31 is listed as the latest release. Its tag has a verified committer signature, although the signing key has expired.