GKrellM vs Nexus

GKrellM is a free system-monitoring program that stacks multiple readings in one interface and supports themes matching a window manager, GTK or another theme. Its built-in monitors cover CPU, processes, disks, network interfaces, memory, swap, filesystems, uptime and internet connections. When supported by the system’s hardware and software, temperature, fan and voltage monitors can show configurable warnings and alarms. A mailbox monitor checks mbox, maildir, MH, POP3 and IMAP mailboxes, and can launch a mail reader or mail-checking program. GKrellM can also run as a client and collect data from a gkrellmd server on a remote machine. Both the program and server support plugins for specialized monitors. Builds or compilation options are listed for Linux, FreeBSD, Mac OS X, NetBSD, OpenBSD and Windows. GKrellM requires GTK, GDK and GLib; the server requires GLib and can be installed without GTK or X libraries. It is released under the GNU General Public License at no cost.

Nexus combines PC hardware monitoring, fan and pump control, and RGB lighting in one free app. It shows live CPU, GPU, memory, network, disk, fan, and temperature readings, with per-game FPS history on Windows. Its GPU-rendered lighting engine offers screen sync, audio sync, and Game Sync. Users can set fan and pump curves from any system temperature sensor or leave selected devices on BIOS or firmware settings. Nexus uses its own device drivers and a bundled OpenRGB build; hardware support depends on the exact model. A phone browser can act as a remote panel, using an encrypted relay outside the home network and switching to a direct connection when possible. The app works locally and offline without an account, while optional anonymous telemetry can be controlled in settings. Nexus runs on 64-bit Windows 10 or 11, Apple Silicon Macs, and x86-64 Linux. It has no builds for Windows on ARM, Intel Macs, or ARM Linux. Companion iOS and Android apps are not yet in the app stores.