{"id":186,"date":"2015-03-29T11:42:49","date_gmt":"2015-03-29T11:42:49","guid":{"rendered":"http:\/\/blog.soton.ac.uk\/pi\/?p=186"},"modified":"2015-03-29T11:42:49","modified_gmt":"2015-03-29T11:42:49","slug":"parallel-image-processing-test-on-the-new-raspberry-pi-2","status":"publish","type":"post","link":"https:\/\/blog.soton.ac.uk\/pi\/2015\/03\/29\/parallel-image-processing-test-on-the-new-raspberry-pi-2\/","title":{"rendered":"Parallel Image Processing test on the new Raspberry Pi 2"},"content":{"rendered":"<p>Now there are four cores &#8211; and better ones &#8211; I felt the need to run our <a href=\"http:\/\/www.vips.ecs.soton.ac.uk\/index.php?title=Benchmarks\">VIPS benchmarks<\/a> to see how well the cores can work together. \u00a0This is CPU-bound so is not affected by the micro-SD card speeds. Here are my results using vips-7.42.3:<\/p>\n<p>Threads, time(s), speed-up<\/p>\n<p>1, 92, 1<\/p>\n<p>2, 48.2, 1.9 x<\/p>\n<p>3, 32.5, 2.8 x<\/p>\n<p>4, 23.2, 3.96 x<\/p>\n<p>&nbsp;<\/p>\n<p>I ran them in console mode so there were no desktop threads running (although the little CPU meter is interesting if you do that &#8211; showing 25% 50% 75% 100% roughly as you increase the cores used.<\/p>\n<p>Conclusion: the Pi2 is about a quarter of the speed of an old core-2 duo type core and certainly slower than the ARM A15 found in modern tablets\/chromebooks. Parallel processing on the Pi does work well however with a 4 core speed-up of 3.96 times.<\/p>\n<p>Kirk<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Now there are four cores &#8211; and better ones &#8211; I felt the need to run our VIPS benchmarks to see how well the cores can work together. \u00a0This is CPU-bound so is not affected by the micro-SD card speeds. Here are my results using vips-7.42.3: Threads, time(s), speed-up 1, 92, 1 2, 48.2, 1.9 &hellip; <\/p>\n<p><a class=\"more-link block-button\" href=\"https:\/\/blog.soton.ac.uk\/pi\/2015\/03\/29\/parallel-image-processing-test-on-the-new-raspberry-pi-2\/\">Continue reading &raquo;<\/a><\/p>\n","protected":false},"author":71670,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-186","post","type-post","status-publish","format-standard","hentry","category-uncategorized"],"_links":{"self":[{"href":"https:\/\/blog.soton.ac.uk\/pi\/wp-json\/wp\/v2\/posts\/186","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/blog.soton.ac.uk\/pi\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/blog.soton.ac.uk\/pi\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/blog.soton.ac.uk\/pi\/wp-json\/wp\/v2\/users\/71670"}],"replies":[{"embeddable":true,"href":"https:\/\/blog.soton.ac.uk\/pi\/wp-json\/wp\/v2\/comments?post=186"}],"version-history":[{"count":1,"href":"https:\/\/blog.soton.ac.uk\/pi\/wp-json\/wp\/v2\/posts\/186\/revisions"}],"predecessor-version":[{"id":187,"href":"https:\/\/blog.soton.ac.uk\/pi\/wp-json\/wp\/v2\/posts\/186\/revisions\/187"}],"wp:attachment":[{"href":"https:\/\/blog.soton.ac.uk\/pi\/wp-json\/wp\/v2\/media?parent=186"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blog.soton.ac.uk\/pi\/wp-json\/wp\/v2\/categories?post=186"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blog.soton.ac.uk\/pi\/wp-json\/wp\/v2\/tags?post=186"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}