A system monitor is a hardware or

software Software consists of computer programs that instruct the Execution (computing), execution of a computer. Software also includes design documents and specifications. The history of software is closely tied to the development of digital comput ...

component used to monitor

system resources A system is a group of interacting or interrelated elements that act according to a set of rules to form a unified whole. A system, surrounded and influenced by its environment, is described by its boundaries, structure and purpose and is exp ...

and performance in a computer system. Among the management issues regarding use of system monitoring tools are resource usage and privacy. Monitoring can track both input and output values and events of systems.

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 usage and frequency, or the amount of free

RAM Ram, ram, or RAM most commonly refers to: * A male sheep * Random-access memory, computer memory * Ram Trucks, US, since 2009 ** List of vehicles named Dodge Ram, trucks and vans ** Ram Pickup, produced by Ram Trucks Ram, ram, or RAM may also ref ...

. 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 assigned to a device connected to a computer network that uses the Internet Protocol for communication. IP addresses serve two main functions: network interface i ...

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 A computer case, also known as a computer chassis, is the enclosure that contains most of the hardware of a personal computer. The components housed inside the case (such as the CPU, motherboard, memory, mass storage devices, power supply unit ...

, 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, developed by USB Implementers Forum (USB-IF), for digital data transmission and power delivery between many types of electronics. It specifies the architecture, in particular the physical ...

. 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 to display information. Liquid crystals do not em ...

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. The primary function of a few very high-end models of hardware system monitor is to interface with only a specific model of

motherboard A motherboard, also called a mainboard, a system board, a logic board, and informally a mobo (see #Nomenclature, "Nomenclature" section), is the main printed circuit board (PCB) in general-purpose computers and other expandable systems. It ho ...

. 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 The System Management Bus (SMBus or SMB) is a single-ended simple two-wire bus for the purpose of lightweight communication. Most commonly it is found in chipsets of computer motherboards for communication with the power source for ON/OFF instru ...

, or as part of a Super I/O solution, often interfaced through Low Pin Count (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 a manufactured 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 control is the management of the rotational speed of an electric fan. In computers, various types of computer fans are used to provide adequate cooling, and different fan control mechanisms balance their cooling capacities and noise they gen ...

ling capabilities. System monitoring software like SpeedFan 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 ...

on Linux, envstat on NetBSD, and sysctl hw.sensors on OpenBSD and DragonFly can interface with these chips to relay this environmental

sensor A sensor is often defined as a device that receives and responds to a signal or stimulus. The stimulus is the quantity, property, or condition that is sensed and converted into electrical signal. In the broadest definition, a sensor is a devi ...

information to the user.

Privacy

When an individual user is measuring the performance of a single-user system, whether it is a standalone box or a

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

on a multi-user system, 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 "cause the OS to crash".

List of software monitors

Single system: *

Activity Monitor This is a list of built-in apps and system components developed by Apple Inc. for macOS that come bundled by default or are installed through a system update. Many of the default programs found on macOS have counterparts on Apple's other operat ...

* AIDA64 *

CPU-Z CPU-Z is a freeware system profiler, system profiling and system monitor, monitoring application for Microsoft Windows and Android (operating system), Android that detects the central processing unit, Random access memory, RAM, motherboard chipse ...

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 d ...

* Conky *

htop htop is an interactive system monitor process viewer and process manager. It is designed as an alternative to the Unix program top (software), top. It shows a frequently updated list of the processes running on a computer, normally ordered by t ...

* hw.sensors on OpenBSD and DragonFly BSD *

iftop Iftop is a free software command-line system monitor tool developed by Paul Warren. It produces a real-time stream of incoming and outgoing network communications from the operating system iftop is running within. By default, the connections are ...

* iostat * KDE System Guard (KSysguard) *

* monit * Monitorix * Motherboard Monitor * Netdata * nmon * ntop * Process Explorer * Resource Monitor (resmon) * Samurize * Sar in UNIX * SpeedFan * sysmon/ envsys on NetBSD * systat *

System Monitor A system monitor is a hardware or software 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. Monitoring can tra ...

(sysmon) *

top Top most commonly refers to: * Top, a basic term of orientation, distinguished from bottom, front, back, and sides * Spinning top, a ubiquitous traditional toy * Top (clothing), clothing designed to be worn over the torso * Mountain top, a moun ...

* vmstat *

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 feature ...

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 names of ...

Distributed: * Argus (monitoring software) * Collectd *

Ganglia A ganglion (: ganglia) 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 a ...

* GKrellM * HP SiteScope * Icinga * monit (paid version M/monit) * NMIS * Munin *

Nagios Nagios is an event monitoring system that offers monitoring and alerting services for servers, switches, applications and services. It alerts users when things go wrong and alerts them a second time when the problem has been resolved. Ethan ...

* NetCrunch * Opmantek * Pandora FMS * Performance Monitor (perfmon) *

Prometheus (software) Prometheus is a free software application used for event monitoring and alerting. It records metrics in a time series database (allowing for high dimensionality) built using an HTTP pull model, with flexible queries and real-time alerting. Th ...

* symon * Vigilo NMS (Enterprise Editions) * Zenoss Core

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 an American 501(c)(3) organization, 501(c)(3) public charity professional organization for electrical engineering, electronics engineering, and other related disciplines. The IEEE ...

, 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