{"id":3064,"date":"2018-11-11T23:44:55","date_gmt":"2018-11-11T23:44:55","guid":{"rendered":"https:\/\/www.appservgrid.com\/paw92\/?p=3064"},"modified":"2018-11-12T02:50:31","modified_gmt":"2018-11-12T02:50:31","slug":"the-performance-impact-of-spectre-mitigation-on-power9","status":"publish","type":"post","link":"https:\/\/www.appservgrid.com\/paw92\/index.php\/2018\/11\/11\/the-performance-impact-of-spectre-mitigation-on-power9\/","title":{"rendered":"The Performance Impact Of Spectre Mitigation On POWER9"},"content":{"rendered":"<p>Over the past year we have looked extensively at the performance impact of <a href=\"https:\/\/www.phoronix.com\/scan.php?page=search&amp;q=Spectre\">Spectre<\/a> mitigations on x86_64 CPUs but now with having the <a href=\"https:\/\/www.phoronix.com\/scan.php?page=news_item&amp;px=Talos-2-Initial-Hands-On\">Raptor Talos II<\/a> in our labs, here are some benchmarks to see the performance impact of IBM&#8217;s varying levels of Spectre mitigation for POWER9.<\/p>\n<p>&nbsp;<\/p>\n<p><a href=\"\/\/www.phoronix.com\/image-viewer.php?id=power9-spectre-benchmarks&amp;image=power9_spectre_perf_lrg\" target=\"_blank\" rel=\"noopener\"><img decoding=\"async\" src=\"\/\/www.phoronix.net\/image.php?id=power9-spectre-benchmarks&amp;image=power9_spectre_perf_med\" \/><\/a><\/p>\n<p>&nbsp;<\/p>\n<p>By default, Raptor Computing Systems ships their system in the safest mode of providing full kernel and user-space protection against Spectre Variant Two. But by editing a file from the OpenBMC environment it&#8217;s possible to control the Spectre protections on their libre hardware. Besides the full\/user protection against Spectre there is also kernel-only protection that is more akin to the protection found on x86_64 CPUs. Additionally, there is the ability to completely disable the protection for yielding the greatest performance (or what would be considered standard pre-2018) but leaving your hardware vulnerable to Spectre. More details on controlling the Spectre protections on Talos II hardware can be found via the <a href=\"https:\/\/wiki.raptorcs.com\/wiki\/POWER\/Spectre_Protections\">RaptorCS.com Wiki<\/a>.<\/p>\n<p>This weekend are some benchmarks for reference of the Talos II Secure Workstation with dual 22-core POWER9 CPUs when tested in the default mode of kernel\/user protection, kernel protection only, and then no protection at all for seeing how the performance compares &#8212; just as we have done many times over the past year for Intel and AMD CPUs too.<\/p>\n<p>These reference benchmarks were done via the <a href=\"https:\/\/www.phoronix-test-suite.com\/\">Phoronix Test Suite<\/a>. If you want to see how your own Linux system(s) compare to the performance of this fully open-source system with libre firmware in its various Spectre configurations, simply run phoronix-test-suite benchmark 1811098-SK-TALOSIIDU15.<\/p>\n<p><a href=\"http:\/\/www.phoronix.com\/vr.php?view=27070\" target=\"_blank\" rel=\"noopener\">Source<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Over the past year we have looked extensively at the performance impact of Spectre mitigations on x86_64 CPUs but now with having the Raptor Talos II in our labs, here are some benchmarks to see the performance impact of IBM&#8217;s varying levels of Spectre mitigation for POWER9. &nbsp; &nbsp; By default, Raptor Computing Systems ships &hellip; <\/p>\n<p class=\"link-more\"><a href=\"https:\/\/www.appservgrid.com\/paw92\/index.php\/2018\/11\/11\/the-performance-impact-of-spectre-mitigation-on-power9\/\" class=\"more-link\">Continue reading<span class=\"screen-reader-text\"> &#8220;The Performance Impact Of Spectre Mitigation On POWER9&#8221;<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-3064","post","type-post","status-publish","format-standard","hentry","category-linux"],"_links":{"self":[{"href":"https:\/\/www.appservgrid.com\/paw92\/index.php\/wp-json\/wp\/v2\/posts\/3064","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.appservgrid.com\/paw92\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.appservgrid.com\/paw92\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.appservgrid.com\/paw92\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.appservgrid.com\/paw92\/index.php\/wp-json\/wp\/v2\/comments?post=3064"}],"version-history":[{"count":1,"href":"https:\/\/www.appservgrid.com\/paw92\/index.php\/wp-json\/wp\/v2\/posts\/3064\/revisions"}],"predecessor-version":[{"id":3277,"href":"https:\/\/www.appservgrid.com\/paw92\/index.php\/wp-json\/wp\/v2\/posts\/3064\/revisions\/3277"}],"wp:attachment":[{"href":"https:\/\/www.appservgrid.com\/paw92\/index.php\/wp-json\/wp\/v2\/media?parent=3064"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.appservgrid.com\/paw92\/index.php\/wp-json\/wp\/v2\/categories?post=3064"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.appservgrid.com\/paw92\/index.php\/wp-json\/wp\/v2\/tags?post=3064"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}