Do you like to verify whether you are using the latest versions of our applications? Just use the Check for Updates menu item in each program or enable its automatic check feature. Or better, use Bresink Software Updater to check, download, and update our software products automatically. For manual verification, you can also use the version overview.

100% systemload I have a large Excel file, almost 100Mb, contains 2 sheets, last cells in Sheet 1: Q807782 Sheet 2: S439813. An alternative configuration of the default Ksysguard SystemLoad tab:- 1 pixel per measure instead of 6- one measure every 5 seconds instead of half second- the yellow receive bar was too bright- the CPUs are stackedI have shared this as I was tired of always hand editing it in new computers.

All our active applications follow Apple's Universal2 standard. They can run natively on Macs with Apple Silicon, optimally supporting the latest Macs with M1 processors.

TinkerTool System 7

TinkerTool System 7 is a collection of system utility features assisting you in performing advanced administration tasks on Apple Macintosh computers. The application makes use of a self-adapting user interface which automatically adjusts to the computer model and to the version of macOS you are running. All options available in the current situation are accessible via “panes”, very similar to the techniques you already know from the System Preferences application. All functions can be controlled by a single program which acts as general toolbox and First Aid assistant. Learn more…

TinkerTool System 6

TinkerTool System 6 is an alternative version of TinkerTool System, designed for the operating systems

supporting their different feature sets. Learn more…

TinkerTool

TinkerTool is an application that gives you access to additional preference settings Apple has built into macOS. This allows to activate hidden features in the operating system and in some of the applications delivered with the system.

The tool makes sure that preference changes can only affect the current user. It will never change any component of the operating system, so the integrity of your system is not put at risk, and there will be no negative effect on system updates. Learn more…

Backup Server Control

Backup Server Control provides a graphical user interface to setup and administer a server for network-based Time Machine® backups with a few mouse clicks on a Macintosh®. Other Macs running macOS Sierra or later can perform backups on the Time Machine server. The current status of network backups can be reviewed any time.

A Time Machine server running on a Mac can be very powerful. It is easy to handle and offers good scaling. By adding new disk drives, the service can be extended any time when needed, matching new requirements for increasing storage sizes or when new computers arrive. Learn more…

System Monitor

Do you like to know which parts of your computer are currently busy? Do you like to monitor the current performance of hard drives and network interfaces? Do you like to keep an eye on the number of write accesses to your precious SSD? Do you like to see which disks are currently in sleep mode? Are you a PC switcher, but you miss the flickering activity lights of disks and interfaces on your Mac? But you like to do all this unobtrusively, with typical Mac design, wasting no screen real estate? Then, System Monitor will be a very interesting app for you. Learn more…

Battery Monitor

More and more computers are mobile devices nowadays. The most important prerequisite for a portable computer is a chargeable battery which keeps the device powered. Batteries are not really cheap replacement parts and they are subject to wear and tear. Their lifetimes should be optimized, handling them with the necessary care. Battery Monitor is a small auxiliary application useful in this regard. It offers the following features: Display of the charge state in the Dock, display of internal battery information, capturing charge and discharge curves, bookkeeping of the aging process of the battery. Learn more…

Sync Checker

Sync Checker is designed to check if two folders or disks are perfectly synchronized, i.e. if they have exactly the same contents. Verify if your backup and sync programs work correctly, find out where two macOS installations differ, test if your web server has received the latest updates of your web pages: There are many situations where Sync Checker can be really helpful.

If file collections are not in sync, Sync Checker will help you to browse through the differing items, analyzing exactly where a mismatch occurred, and if the differences are critical or negligible. Filter tools help you to navigate through large sets of mismatching objects. You can also create a textual report of the results which can be printed or exported. Learn more…

NFS Manager

NFS Manager is a graphical user interface to control all built-in NFS features of macOS. It can manage a whole network of macOS computers to setup a distributed NFS file system via a few simple mouse clicks.

NFS (Network File System) is the industry standard for file sharing on UNIX systems like macOS. Each macOS system can be setup as an NFS server to offer files to the network, or as an NFS client to access files shared by other computers. Different from other file sharing protocols built into macOS, NFS has no limitations in the number of users or connections concurrently active. In addition, NFS can be setup to connect to servers fully automatically (“automounting”) without any password entries being necessary. Learn more…

PrefEdit

PrefEdit is an application to manage nearly all aspects of the preference system contained in every macOS installation. The program consists of three components which are tightly integrated with each other: A browser and editor for the macOS preferences database, a browser and editor for macOS property list files (plists), and a browser for preference manifest files. PrefEdit was the first preferences editor ever published for Mac OS X. With its long experience and maturity, it has become one of the most advanced preference management applications for macOS available today. Learn more..

Bresink Software Updater

If you use many of our software products on your Mac, it can become tedious to keep all of them up-to-date. Bresink Software Updater facilitates the maintenance of our applications considerably. At a glance you can see if all programs are at their latest versions. All necessary steps, such as the download, the security check, and copying the programs to their usual places on your computer can be performed automatically in no time. Learn more…

SystemLoad

SystemLoad is a diagnostic application assisting you in the detection of cooling or power supply problems with Apple Macintosh computers. The tool can put a user-definable load onto one or more processors. This can help in diagnosing the following issues: problems with the cooling system or temperature sensors, problems with chirping noise caused by oscillating parts in the voltage supply circuitry of specific computer models, problems with battery units of portable computers. Learn more…

End-of-Life Products

Hardware Monitor is an application to read out hardware sensors in Macintosh computers. Several hundred sensors in more than 70 model series are supported. The program can display and visualize measured values in a large variety of fashions, including speech output. Readings can be stored and exported. In addition, artificial software sensors monitoring macOS can be defined, and external LCD units can be controlled. The application also allows you to explore other technical data of your computer, like exact processor type, logicboard data, battery, display, and drive information, or manufacturing details.

The program Hardware Monitor Remote is an add-on to the program Hardware Monitor for the macOS operating system. Hardware Monitor Remote allows you to use a hardware monitoring service on a remote Macintosh system. Other computers can contact this system via network to receive readings from all available hardware sensors. You can connect to an unlimited number of computer simultaneously and monitor them all from a single workstation.

Legacy Software Products

Temperature Monitor and other software products for use with operating systems prior to macOS 10.12 Sierra can be found on the page for vintage and obsolete computers.

In UNIXcomputing, the system load is a measure of the amount of computational work that a computer system performs. The load average represents the average system load over a period of time. It conventionally appears in the form of three numbers which represent the system load during the last one-, five-, and fifteen-minute periods.

Unix-style load calculation[edit]

All Unix and Unix-like systems generate a dimensionless metric of three 'load average' numbers in the kernel. Users can easily query the current result from a Unix shell by running the uptime command:

The w and top commands show the same three load average numbers, as do a range of graphical user interface utilities. In Linux, they can also be accessed by reading the /proc/loadavg file.

An idle computer has a load number of 0 (the idle process isn't counted). Each process using or waiting for CPU (the ready queue or run queue) increments the load number by 1. Each process that terminates decrements it by 1. Most UNIX systems count only processes in the running (on CPU) or runnable (waiting for CPU) states. However, Linux also includes processes in uninterruptible sleep states (usually waiting for disk activity), which can lead to markedly different results if many processes remain blocked in I/O due to a busy or stalled I/O system.^[1] This, for example, includes processes blocking due to an NFS server failure or too slow media (e.g., USB 1.x storage devices). Such circumstances can result in an elevated load average which does not reflect an actual increase in CPU use (but still gives an idea of how long users have to wait).

Systems calculate the load average as the exponentially damped/weighted moving average of the load number. The three values of load average refer to the past one, five, and fifteen minutes of system operation.^[2]

Mathematically speaking, all three values always average all the system load since the system started up. They all decay exponentially, but they decay at different speeds: they decay exponentially by e after 1, 5, and 15 minutes respectively. Hence, the 1-minute load average consists of 63% (more precisely: 1 - 1/e) of the load from the last minute and 37% (1/e) of the average load since start up, excluding the last minute. For the 5- and 15-minute load averages, the same 63%/37% ratio is computed over 5 minutes and 15 minutes respectively. Therefore, it is not technically accurate that the 1-minute load average only includes the last 60 seconds of activity, as it includes 37% of the activity from the past, but it is correct to state that it includes mostly the last minute.

Interpretation[edit]

For single-CPU systems that are CPU bound, one can think of load average as a measure of system utilization during the respective time period. For systems with multiple CPUs, one must divide the load by the number of processors in order to get a comparable measure.

For example, one can interpret a load average of '1.73 0.60 7.98' on a single-CPU system as:

• during the last minute, the system was overloaded by 73% on average (1.73 runnable processes, so that 0.73 processes had to wait for a turn for a single CPU system on average).
• during the last 5 minutes, the CPU was idling 40% of the time on average.
• during the last 15 minutes, the system was overloaded 698% on average (7.98 runnable processes, so that 6.98 processes had to wait for a turn for a single CPU system on average).

This means that this system (CPU, disk, memory, etc.) could have handled all of the work scheduled for the last minute if it were 1.73 times as fast.

In a system with four CPUs, a load average of 3.73 would indicate that there were, on average, 3.73 processes ready to run, and each one could be scheduled into a CPU.

On modern UNIX systems, the treatment of threading with respect to load averages varies. Some systems treat threads as processes for the purposes of load average calculation: each thread waiting to run will add 1 to the load. However, other systems, especially systems implementing so-called M:N threading, use different strategies such as counting the process exactly once for the purpose of load (regardless of the number of threads), or counting only threads currently exposed by the user-thread scheduler to the kernel, which may depend on the level of concurrency set on the process. Linux appears to count each thread separately as adding 1 to the load.^[3]

CPU load vs CPU utilization[edit]

The comparative study of different load indices carried out by Ferrari et al.^[4] reported that CPU load information based upon the CPU queue length does much better in load balancing compared to CPU utilization. The reason CPU queue length did better is probably because when a host is heavily loaded, its CPU utilization is likely to be close to 100% and it is unable to reflect the exact load level of the utilization. In contrast, CPU queue lengths can directly reflect the amount of load on a CPU. As an example, two systems, one with 3 and the other with 6 processes in the queue, are both very likely to have utilizations close to 100% although they obviously differ.^{[original research?]}

Reckoning CPU load[edit]

On Linux systems, the load-average is not calculated on each clock tick, but driven by a variable value that is based on the HZ frequency setting and tested on each clock tick. This setting defines the kernel clock tick rate in Hertz (times per second), and it defaults to 100 for 10ms ticks. Kernel activities use this number of ticks to time themselves. Specifically, the timer.c::calc_load() function, which calculates the load average, runs every LOAD_FREQ = (5*HZ+1) ticks, or about every five seconds:

The avenrun array contains 1-minute, 5-minute and 15-minute average. The CALC_LOAD macro and its associated values are defined in sched.h:

The 'sampled' calculation of load averages is a somewhat common behavior; FreeBSD, too, only refreshes the value every five seconds. The interval is usually taken to not be exact so that they do not collect processes that are scheduled to fire at a certain moment.^[5]

A post on the Linux mailing list considers its +1 tick insufficient to avoid Moire artifacts from such collection, and suggests an interval of 4.61 seconds instead.^[6] This change is common among Android system kernels, although the exact expression used assumes an HZ of 100.^[7]

Other system performance commands[edit]

Other commands for assessing system performance include:

• uptime – the system reliability and load average
• top – for an overall system view
• vmstat – vmstat reports information about runnable or blocked processes, memory, paging, block I/O, traps, and CPU.
• htop – interactive process viewer
• dstat – helps correlate all existing resource data for processes, memory, paging, block I/O, traps, and CPU activity.
• iftop – interactive network traffic viewer per interface
• nethogs – interactive network traffic viewer per process
• iotop – interactive I/O viewer^[8]
• iostat – for storage I/O statistics
• netstat – for network statistics
• mpstat – for CPU statistics
• tload – load average graph for terminal
• xload – load average graph for X
• /proc/loadavg – text file containing load average

See also[edit]

External links[edit]

• Brendan Gregg (8 August 2017). 'Linux Load Averages: Solving the Mystery'. Retrieved 22 January 2018.
• Neil J. Gunther. 'UNIX Load Average – Part 1: How It Works'(PDF). TeamQuest. Retrieved 12 August 2009.
• Andre Lewis (31 July 2009). 'Understanding Linux CPU Load – when should you be worried?'. Retrieved 21 July 2011. Explanation using an illustrated traffic analogy.
• Ray Walker (1 December 2006). 'Examining Load Average'. Linux Journal. Retrieved 21 July 2011.
• Karsten Becker. 'Linux OSS load monitoring toolset'. LoadAvg.

System Loadlibrary

References[edit]

System Load Indicator

1. ^http://linuxtechsupport.blogspot.com/2008/10/what-exactly-is-load-average.html
2. ^Walker, Ray (1 December 2006). 'Examining Load Average'. Linux Journal. Retrieved 13 March 2012.
3. ^See http://serverfault.com/a/524818/27813
4. ^Ferrari, Domenico; and Zhou, Songnian; 'An Empirical Investigation of Load Indices For Load Balancing Applications', Proceedings of Performance '87, the 12th International Symposium on Computer Performance Modeling, Measurement, and Evaluation, North Holland Publishers, Amsterdam, The Netherlands, 1988, pp. 515–528
5. ^'How is load average calculated on FreeBSD?'. Unix & Linux Stack Exchange.
6. ^Ripke, Klaus (2011). 'Linux-Kernel Archive: LOAD_FREQ (4*HZ+61) avoids loadavg Moire'. lkml.iu.edu.graph & patch
7. ^'Patch kernel with the 4.61s load thing · Issue #2109 · AOSC-Dev/aosc-os-abbs'. GitHub.
8. ^http://man7.org/linux/man-pages/man8/iotop.8.html

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