bottom (btm) vs nmon

bottom is a free graphical system and process monitor that runs in a terminal on Linux, macOS and Windows. It charts CPU use for each core and as an average, along with RAM and swap over time. Network and disk I/O are graphed too, with a control for zooming the displayed time interval. Its process widget lets users display, sort and search process information, use tree mode and send kill signals. Other widgets show disk capacity and use, temperature sensors and battery use. Appearance and behavior can be changed through command-line options or a configuration file, including themes, layout, widget behavior and filtering. An htop-inspired basic mode offers a simpler view, and a selected widget can be expanded to fill the terminal. A read-only option blocks actions that affect the system, such as stopping processes. Installation is documented through package managers, Cargo and pre-built release binaries. Official platform support covers macOS, Linux and Windows; architecture support varies by system. Android and some other systems may work unofficially with limited testing and support.

nmon is a free Linux tool for systems administration, tuning, and performance benchmarking. It collects system information and presents live readings in a terminal through a curses interface. Keyboard controls let operators turn individual data categories on or off. The display can include CPU, memory, network, disks, filesystems, NFS, top processes, and, in the Linux version, resources and processors. Captured readings can be written to a comma-separated file for later analysis or longer-term recording. nmonchart converts output into webpage graphs, while nmon Analyser loads files into Excel and creates graphs. njmon injectors can add JSON data to InfluxDB and Splunk, with real-time graphing through InfluxDB and Grafana. Binaries are listed for POWER, x86, x86_64, mainframe, and ARM Linux. Unsupported distributions require compiling with GCC and the ncurses development library. The Linux project is GPLv3; AIX nmon is integrated into topas and is not open source.