{"id":1089,"date":"2011-07-04T11:36:25","date_gmt":"2011-07-04T09:36:25","guid":{"rendered":"http:\/\/oldblogs.uct.ac.za\/blog\/big-bytes\/2011\/07\/04\/load-shedding"},"modified":"2022-09-26T20:01:58","modified_gmt":"2022-09-26T18:01:58","slug":"power-disruptions","status":"publish","type":"post","link":"https:\/\/ucthpc.uct.ac.za\/index.php\/2011\/07\/04\/power-disruptions\/","title":{"rendered":"Power disruptions"},"content":{"rendered":"Power to the Rondebosch area dropped again this morning, once for 2 minutes and then a brief brownout just after 11:30.\u00a0 We are assured that this is not \"load shedding\" by Eskom, although this is of little relief to anyone running long term work on a desktop not attached to a UPS.\u00a0 Even with a UPS unless a significant investment has been made in batteries a desktop machine will not stay up for more than an hour, and in the case of number crunching with the CPUs working at maximum capacity, this will drain a UPS's batteries at a much higher rate than most desktop computers.\u00a0 While laptops may stay up a bit longer they are not good value for money for HPC from a $\/core perspective.\r\n\r\nFortunately our HPC and Grid clusters are located in UCT's data centres, each with its own UPS and in-line generator.\u00a0 So when our campus wide monitoring system looks like a christmas tree...\r\n\r\n<img src=\"https:\/\/ucthpc.uct.ac.za\/wp-content\/uploads\/2015\/07\/power.png\" alt=\"Power alerts\" border=\"0\" \/>\r\n\r\n...our HPC users can be assured that their jobs are still ticking away.","protected":false},"excerpt":{"rendered":"<p>Power to the Rondebosch area dropped again this morning, once for 2 minutes and then a brief brownout just after 11:30.&nbsp; We are assured that this is not &#8220;load shedding&#8221; by Eskom, although this is of little relief to anyone running long term work on a desktop not attached to a UPS.&nbsp; Even with a UPS unless a significant investment has been made in batteries a desktop machine will not stay up for more than an hour, and in the case of number crunching with the CPUs working at maximum capacity, this will drain a UPS&#8217;s batteries at a much higher rate than most desktop computers.&nbsp; While laptops may stay up a bit longer they are not good value for money for HPC from a $\/core perspective.<\/p>\n<p>Fortunately our HPC and Grid clusters are located in UCT&#8217;s data centres, each with its own UPS and in-line generator.&nbsp; So when our campus wide monitoring system looks like a christmas tree&#8230;<\/p>\n<p><img decoding=\"async\" src=\"http:\/\/blogs.uct.ac.za\/gallery\/1253\/power.png\" border=\"0\" alt=\"Power alerts\"><\/p>\n<p>&#8230;our HPC users can be assured that their jobs are still ticking away. <\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":[],"categories":[6,4],"tags":[],"yoast_head":"<!-- This site is optimized with the Yoast SEO plugin v21.4 - 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