Editing World Community Grid (section)

===Potential problems===
[[File:BOINC running-Task mgr CPU usage history demo-en-1.png|right|thumb|250px|The picture shows particular two CPU usage history (under [[Hyper-threading]]) when [[BOINC]] client software is processing two tasks on each CPU under [[Microsoft Windows]] XP SP2. CPU usage history indicates almost 0% to 100% swing with peak to peak of 3 seconds [[Interval (time)|interval]], when view +update speed set to high, at first half recording period. The rest of half period of history is set to update speed normal, and upper CPU usage history indicates slightly more than 60% and lower CPU usage history show 35% approx. in average.]]
The World Community Grid software increases [[CPU]] usage by consuming unused processing time; in the late 1990s and early 2000s, such calculations were meant to reduce "wasted" CPU cycles.<ref>{{Cite web | url=http://www.sharewarejunkies.com/9zwd11/setihome.htm | title=SETI@Home | access-date=2017-07-28 | archive-date=2019-03-03 | archive-url=https://web.archive.org/web/20190303222604/http://www.sharewarejunkies.com/9zwd11/setihome.htm | url-status=live }}</ref> With modern CPUs, where [[dynamic frequency scaling]] is prevalent, increased usage makes the processor run at higher frequency,<ref>Although on [[Linux]] systems the [https://www.kernel.org/doc/Documentation/cpu-freq/governors.txt CPUfreq frequency scaling governor can be configured otherwise] {{Webarchive|url=https://web.archive.org/web/20170607174541/https://www.kernel.org/doc/Documentation/cpu-freq/governors.txt |date=2017-06-07 }} with the parameter ignore_nice_load.</ref> increasing power usage and heating counter to [[power management]]. Additionally, because of an increasing focus on power performance,<ref>{{Cite web | url=https://www.cpubenchmark.net/power_performance.html | title=PassMark CPU TDP Chart - Performance / Power of available CPUs | access-date=2017-07-28 | archive-date=2017-07-29 | archive-url=https://web.archive.org/web/20170729022431/https://www.cpubenchmark.net/power_performance.html | url-status=live }}</ref> or [[performance per watt]], connecting old/inefficient computers to the grid will increase the total/average power required to complete the same calculations.

The [[BOINC]] client avoids slowing the computer by using a variety of limits that suspend computation when there are insufficient free resources. Unlike other BOINC projects, World Community Grid set the BOINC defaults conservatively, making the chances of computer damage extremely small. The default CPU throttle is 60%. The throttle is coarse-grained; for example, if usage is set to 60% it will work at 100% for 3 seconds, then at 0% for 2 seconds, resulting in an average decrease of processor use.<ref>{{cite web
|url=http://www.worldcommunitygrid.org/help/viewTopic.do?shortName=cpuuse#33
|title=CPU Usage: Why does my PC show high CPU use?
|work=Help
|publisher=World Community Grid
|access-date=2007-08-05
|archive-date=2007-07-14
|archive-url=https://web.archive.org/web/20070714084446/http://www.worldcommunitygrid.org/help/viewTopic.do?shortName=cpuuse#33
|url-status=live
}}</ref>

An add-on program for Windows computers – [http://efmer.eu/boinc/ TThrottle] – can solve the problem of overheating by directly limiting the BOINC project's use of the host computer. It does this by measuring the CPU and/or the GPU temperature and adjusts the run time accordingly. It also uses a shorter switching time of less than one second, resulting in less temperature change during switching.{{citation needed|date=May 2017}}