A system monitor is a hardware or

software Software is a set of computer programs and associated documentation and data. This is in contrast to hardware, from which the system is built and which actually performs the work. At the lowest programming level, executable code consists ...

component used to monitor system resources and performance in a computer system. Among the management issues regarding use of system monitoring tools are resource usage and privacy.

Overview

Software monitors occur more commonly, sometimes as a part of a widget engine. These monitoring systems are often used to keep track of system resources, such as

CPU A central processing unit (CPU), also called a central processor, main processor or just processor, is the electronic circuitry that executes instructions comprising a computer program. The CPU performs basic arithmetic, logic, controlling, and ...

usage and frequency, or the amount of free RAM. They are also used to display items such as free space on one or more hard drives, the temperature of the CPU and other important components, and networking information including the system

IP address An Internet Protocol address (IP address) is a numerical label such as that is connected to a computer network that uses the Internet Protocol for communication.. Updated by . An IP address serves two main functions: network interface ident ...

and current rates of upload and download. Other possible displays may include the date and time, system uptime, computer name, username, hard drive S.M.A.R.T. data, fan speeds, and the voltages being provided by the power supply. Less common are hardware-based systems monitoring similar information. Customarily these occupy one or more

drive bay A drive bay is a standard-sized area for adding hardware to a computer. Most drive bays are fixed to the inside of a case, but some can be removed. Over the years since the introduction of the IBM PC, it and its compatibles have had many form f ...

s on the front of the computer case, and either interface directly with the system hardware or connect to a software data-collection system via

USB Universal Serial Bus (USB) is an industry standard that establishes specifications for cables, connectors and protocols for connection, communication and power supply (interfacing) between computers, peripherals and other computers. A broad v ...

. With either approach to gathering data, the monitoring system displays information on a small

LCD A liquid-crystal display (LCD) is a flat-panel display or other electronically modulated optical device that uses the light-modulating properties of liquid crystals combined with polarizers. Liquid crystals do not emit light directly but in ...

panel or on series of small analog or LED numeric displays. Some hardware-based system monitors also allow direct control of fan speeds, allowing the user to quickly customize the cooling in the system. A few very high-end models of hardware system monitor are designed to interface with only a specific model of

motherboard A motherboard (also called mainboard, main circuit board, mb, mboard, backplane board, base board, system board, logic board (only in Apple computers) or mobo) is the main printed circuit board (PCB) in general-purpose computers and other expand ...

. These systems directly utilize the sensors built into the system, providing more detailed and accurate information than less-expensive monitoring systems customarily provide.

Software monitoring

Software monitoring tools operate within the device they're monitoring.

Hardware monitoring

Unlike software monitoring tools, hardware measurement tools can either located within the device being measure, or they can be attached and operate from an external location. A hardware monitor is a common component of modern

s, which can either come as a separate chip, often interfaced through I²C or SMBus, or as part of a Super I/O solution, often interfaced through

Low Pin Count The Low Pin Count (LPC) bus is a computer bus used on IBM-compatible personal computers to connect low-bandwidth devices to the CPU, such as the BIOS ROM (BIOS ROM was moved to the Serial Peripheral Interface (SPI) bus in 2006), "legacy" I/O ...

(LPC). These devices make it possible to monitor temperature in the

chassis A chassis (, ; plural ''chassis'' from French châssis ) is the load-bearing framework of an artificial object, which structurally supports the object in its construction and function. An example of a chassis is a vehicle frame, the underpart ...

, voltage supplied to the motherboard by the power supply unit and the speed of the computer fans that are connected directly to one of the fan headers on the motherboard. Many of these hardware monitors also have

fan control Fan commonly refers to: * Fan (machine), a machine for producing airflow, often used for cooling ** Hand fan, an implement held and waved by hand to move air for cooling * Fan (person), short for fanatic; an enthusiast or supporter, especially wit ...

ling capabilities. System monitoring software like

SpeedFan SpeedFan is a system monitor for Microsoft Windows that can read temperatures, voltages and fan speeds of computer components. It can change computer fan speeds depending on the temperature of various components. The program can display system v ...

on Windows,

lm_sensors lm_sensors (Linux-monitoring sensors) is a free open-source software-tool for Linux that provides tools and drivers for monitoring temperatures, voltage, humidity, and fans. It can also detect chassis intrusions. Issues During 2001/2004, the l ...

on Linux, envstat on NetBSD, and sysctl

hw.sensors The hw.sensors framework is a kernel-level hardware sensors framework originating from OpenBSD, which uses the sysctl kernel interface as the transport layer between the kernel and the userland. , the framework is used by over a hundred devi ...

on OpenBSD and DragonFly can interface with these chips to relay this environmental

sensor A sensor is a device that produces an output signal for the purpose of sensing a physical phenomenon. In the broadest definition, a sensor is a device, module, machine, or subsystem that detects events or changes in its environment and sends ...

information to the user.

Privacy

When an individual user is measuring the performance of a

single-user system Multi-user software is computer software that allows access by multiple users of a computer. Time-sharing systems are multi-user systems. Most batch processing systems for mainframe computers may also be considered "multi-user", to avoid leaving t ...

, whether it is a standalone box or a

virtual machine In computing, a virtual machine (VM) is the virtualization/emulation of a computer system. Virtual machines are based on computer architectures and provide functionality of a physical computer. Their implementations may involve specialized hardw ...

on a

multi-user system Multi-user software is computer software that allows access by multiple users of a computer. Time-sharing systems are multi-user systems. Most batch processing systems for mainframe computers may also be considered "multi-user", to avoid leavin ...

, access does not impede the

privacy Privacy (, ) is the ability of an individual or group to seclude themselves or information about themselves, and thereby express themselves selectively. The domain of privacy partially overlaps with security, which can include the concepts of a ...

of others. Privacy becomes an issue when someone other than the end-user, such as a system manager, has legitimate need to access data about other users.

Resource usage

When events occur faster than a monitor can record them, a workaround is needed, such as replacing event recording with simple counting. Another consideration is not having major impact on the CPU and storage available for useful work. While a hardware monitor will usually have less impact than a software monitor, there are data items, such as "some descriptive information, such as program names" that must involve software. A further consideration is that a bug in this domain can have severe impact: an extreme case would be "cause the OS to

crash Crash or CRASH may refer to: Common meanings * Collision, an impact between two or more objects * Crash (computing), a condition where a program ceases to respond * Cardiac arrest, a medical condition in which the heart stops beating * Couch su ...

List of software monitors

Single system: * Activity Monitor *

AIDA64 AIDA64 is a system information, diagnostics, and auditing application developed by FinalWire Ltd (a Hungarian company) that runs on Windows, Android, iOS, Windows Phone, Tizen, ChromeOS and Sailfish OS operating systems. It displays detailed inf ...

CPU-Z CPU-Z is a freeware system profiling and monitoring application for Microsoft Windows and Android that detects the central processing unit, RAM, motherboard chip-set, and other hardware features of a modern personal computer or Android device. ...

GPU-Z TechPowerUp GPU-Z (or just GPU-Z) is a lightweight utility designed to provide information about video cards and GPUs.TechPowerUp The program displays the specifications of Graphics Processing Unit (often shortened to GPU) and its memory; also di ...

* Conky * htop *

on OpenBSD and DragonFly BSD *

iftop Iftop is a free software command-line system monitor tool that produces a frequently updated list of network connections. By default, the connections are ordered by bandwidth usage, with only the "top" bandwidth consumers shown. It is analogous ...

iostat iostat (''input/output statistics'') is a computer system monitor tool used to collect and show operating system storage input and output statistics. It is often used to identify performance issues with storage devices, including local disks, or ...

KDE System Guard KDE System Guard, also known as KSysGuard, is the task manager and performance monitor for the KDE platform on Unix-like systems. It can monitor both local and remote hosts, accomplished via running ksysguardd on the remote host, and having the G ...

(KSysguard) *

monit Monit is a free, open-source process supervision tool for Unix and Linux. With Monit, system status can be viewed directly from the command line, or via the native HTTP(S) web server. Monit is able to do automatic maintenance, repair, and run me ...

* Monitorix *

Motherboard Monitor Motherboard Monitor is a utility designed by Alexander Van Kaam for Microsoft Windows. It provides live information about the state of a motherboard and other hardware, including temperatures, voltages, fan speeds, and more. On July 6, 2004, it w ...

Netdata Netdata is an open source tool designed to collect real-time metrics, such as CPU usage, disk activity, bandwidth usage, website visits, etc., and then display them in live, easy-to-interpret charts. The tool is designed to visualize activity ...

nmon nmon (''Nigel's Monitor'') is a computer performance system monitor tool for the AIX and Linux operating systems. The nmon tool has two modes a) displays the performance stats on-screen in a condensed format or b) the same stats are saved to a co ...

ntop ntop is computer software that probes a computer network to show network use in a way similar to what the program top does for processes. Software In interactive mode, it displays the network status on the user's terminal. In Web mode, it act ...

* Process Explorer *

Resource Monitor Resource Monitor, a utility in Windows Vista and later, displays information about the use of hardware (CPU, memory, disk, and network) and software (file handles and modules) resources in real time. Users can launch Resource Monitor by executin ...

(resmon) * Samurize *

Sar in UNIX System Activity Report (sar) is a Unix System V-derived system monitor command used to report on various system loads, including CPU activity, memory/paging, interrupts, device load, network and swap space utilization. Sar uses /proc filesyst ...

* sysmon/ envsys on NetBSD * systat * System Monitor (sysmon) *

top A spinning top, or simply a top, is a toy with a squat body and a sharp point at the bottom, designed to be spun on its vertical axis, balancing on the tip due to the gyroscopic effect. Once set in motion, a top will usually wobble for a few ...

Vigilo NMS Vigilo NMS (''Network Monitoring System'') is a monitoring software capable of handling large-scale heterogeneous systems (network servers, software) thanks to a distributed and modular architecture. Built around Nagios, Vigilo additionally mana ...

(Community Edition) *

vmstat vmstat (''virtual memory statistics'') is a computer system monitoring tool that collects and displays summary information about operating system memory, processes, interrupts, paging and block I/O. Users of vmstat can specify a sampling interv ...

Windows Desktop Gadgets Windows Desktop Gadgets (called Windows Sidebar in Windows Vista) is a discontinued widget engine for Microsoft Gadgets. Desktop Gadgets have been replaced by Windows 10 Taskbar Widgets. It was introduced with Windows Vista, in which it features ...

Windows Task Manager Task Manager, previously known as Windows Task Manager, is a task manager, system monitor, and startup manager included with Microsoft Windows systems. It provides information about computer performance and running software, including name of r ...

Distributed: * Argus (monitoring software) * Collectd *

Ganglia A ganglion is a group of neuron cell bodies in the peripheral nervous system. In the somatic nervous system this includes dorsal root ganglia and trigeminal ganglia among a few others. In the autonomic nervous system there are both sympatheti ...

* GKrellM * HP SiteScope *

(paid version M/monit) * NMIS * Munin *

Nagios Nagios Core , formerly known as Nagios, is a free and open-source computer-software application that monitors systems, networks and infrastructure. Nagios offers monitoring and alerting services for servers, switches, applications and services. ...

* NetCrunch * Opmantek *

Pandora FMS Pandora FMS (for ''Pandora Flexible Monitoring System'') is software for monitoring computer networks. Pandora FMS allows the visual monitoring of the status and performance of several parameters from different operating systems, servers, appli ...

* Performance Monitor (perfmon) * Prometheus (software) * symon *

(Enterprise Editions) *

Zenoss Core The company Zenoss, Inc. was founded in 2005 and is headquartered in Austin, Texas. The company develops hybrid IT monitoring and analytics software. Zenoss Community Edition was a free and open-source application, server, and network management ...

References

{{reflist, refs= {{Cite conference , author= Constantine A. Murenin , date= 2007-04-17 , url = http://sensors.cnst.su/IEEE_ICNSC_2007 , title= Generalised Interfacing with Microprocessor System Hardware Monitors , conference= Proceedings of 2007 IEEE International Conference on Networking, Sensing and Control, 15–17 April 2007. , location= London, United Kingdom , publisher=

IEEE The Institute of Electrical and Electronics Engineers (IEEE) is a 501(c)(3) professional association for electronic engineering and electrical engineering (and associated disciplines) with its corporate office in New York City and its operation ...

, doi = 10.1109/ICNSC.2007.372901 , isbn = 978-1-4244-1076-7 , id = IEEE ICNSC 2007, pp. 901—906.

External links

Monitoring a Linux System with X11/Console/Web-Based Tools
Computer peripherals Liquid crystal displays System administration Utility software types