{"id":9,"date":"2009-07-23T09:47:47","date_gmt":"2009-07-23T14:47:47","guid":{"rendered":"http:\/\/press.mcs.anl.gov\/darshan\/?p=3"},"modified":"2009-07-23T09:47:47","modified_gmt":"2009-07-23T14:47:47","slug":"testpio-case-study-1","status":"publish","type":"post","link":"https:\/\/wordpress.cels.anl.gov\/darshan\/2009\/07\/23\/testpio-case-study-1\/","title":{"rendered":"Testpio Case Study #1"},"content":{"rendered":"<p>Last week I did some comparative runs of the &#8220;testpio&#8221; kernel to find out why pnetcdf I\/O was slower than raw binary MPI-IO.  In this scenario, 512 cores write a 51MB file ten times.<br \/>\nThere were some minor differences:\u00a0 binary (MPI-IO) uses a blockindexed type, while pnetcdf uses subarray.\u00a0 Pnetcdf syncs the file a few more times &#8211; pnetcdf calls MPI_FILE_SYNC when exiting define mode, but I think we will change that soon.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Last week I did some comparative runs of the &#8220;testpio&#8221; kernel to find out why pnetcdf I\/O was slower than raw binary MPI-IO. In this scenario, 512 cores write a 51MB file ten times. There were some minor differences:\u00a0 binary (MPI-IO) uses a blockindexed type, while pnetcdf uses subarray.\u00a0 Pnetcdf syncs the file a few &#8230; <a title=\"Testpio Case Study #1\" class=\"read-more\" href=\"https:\/\/wordpress.cels.anl.gov\/darshan\/2009\/07\/23\/testpio-case-study-1\/\" aria-label=\"Read more about Testpio Case Study #1\">Read more<\/a><\/p>\n","protected":false},"author":444,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"_monsterinsights_skip_tracking":false,"_monsterinsights_sitenote_active":false,"_monsterinsights_sitenote_note":"","_monsterinsights_sitenote_category":0,"footnotes":""},"categories":[1],"tags":[2,3,5,7],"class_list":["post-9","post","type-post","status-publish","format-standard","hentry","category-uncategorized","tag-bluegene","tag-casestudy","tag-climate","tag-testpio"],"acf":[],"_links":{"self":[{"href":"https:\/\/wordpress.cels.anl.gov\/darshan\/wp-json\/wp\/v2\/posts\/9","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/wordpress.cels.anl.gov\/darshan\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/wordpress.cels.anl.gov\/darshan\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/wordpress.cels.anl.gov\/darshan\/wp-json\/wp\/v2\/users\/444"}],"replies":[{"embeddable":true,"href":"https:\/\/wordpress.cels.anl.gov\/darshan\/wp-json\/wp\/v2\/comments?post=9"}],"version-history":[{"count":0,"href":"https:\/\/wordpress.cels.anl.gov\/darshan\/wp-json\/wp\/v2\/posts\/9\/revisions"}],"wp:attachment":[{"href":"https:\/\/wordpress.cels.anl.gov\/darshan\/wp-json\/wp\/v2\/media?parent=9"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/wordpress.cels.anl.gov\/darshan\/wp-json\/wp\/v2\/categories?post=9"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/wordpress.cels.anl.gov\/darshan\/wp-json\/wp\/v2\/tags?post=9"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}