{"id":135,"date":"2013-08-09T09:20:17","date_gmt":"2013-08-09T07:20:17","guid":{"rendered":"http:\/\/svalgaard.net\/jens\/blog\/?p=135"},"modified":"2013-08-09T09:22:56","modified_gmt":"2013-08-09T07:22:56","slug":"turn-off-cpu-throttling","status":"publish","type":"post","link":"https:\/\/svalgaard.net\/jens\/blog\/2013\/08\/turn-off-cpu-throttling\/","title":{"rendered":"Turn off CPU Throttling"},"content":{"rendered":"<p>Some CPU&#8217;s use CPU throttling to reduce the speed of the CPU when it is not in heavy use<!--more--> (to reduce power consumption). In some cases you might want to turn this off, e.g., when measuring CPU performance for the ATLAS libraries.<\/p>\n<p>On CentOS, you turn CPU throttling off in two steps: (must be run as root)<\/p>\n<p><code><br \/>\n\/etc\/init.d\/cpuspeed stop<br \/>\nfor i in \/sys\/devices\/system\/cpu\/cpu*\/cpufreq\/scaling_governor ; do echo performance > $i ; done<br \/>\n<\/code><\/p>\n<p>The first line, only stops the internal daemon that regulates the CPU speed. The 2nd line (the for loop) ensures that, all CPUs switch to <i>performance<\/i> mode (instead of possible running in <i>ondemand<\/i> mode).<\/p>\n<p>You switch back by simply starting the cpuspeed daemon again:<br \/>\n<code><br \/>\n\/etc\/init.d\/cpuspeed start<br \/>\n<\/code><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Some CPU&#8217;s use CPU throttling to reduce the speed of the CPU when it is not in heavy use<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[4],"tags":[],"class_list":["post-135","post","type-post","status-publish","format-standard","hentry","category-linux"],"_links":{"self":[{"href":"https:\/\/svalgaard.net\/jens\/blog\/wp-json\/wp\/v2\/posts\/135","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/svalgaard.net\/jens\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/svalgaard.net\/jens\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/svalgaard.net\/jens\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/svalgaard.net\/jens\/blog\/wp-json\/wp\/v2\/comments?post=135"}],"version-history":[{"count":5,"href":"https:\/\/svalgaard.net\/jens\/blog\/wp-json\/wp\/v2\/posts\/135\/revisions"}],"predecessor-version":[{"id":140,"href":"https:\/\/svalgaard.net\/jens\/blog\/wp-json\/wp\/v2\/posts\/135\/revisions\/140"}],"wp:attachment":[{"href":"https:\/\/svalgaard.net\/jens\/blog\/wp-json\/wp\/v2\/media?parent=135"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/svalgaard.net\/jens\/blog\/wp-json\/wp\/v2\/categories?post=135"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/svalgaard.net\/jens\/blog\/wp-json\/wp\/v2\/tags?post=135"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}