{"id":150,"date":"2010-04-11T11:49:00","date_gmt":"2010-04-11T11:49:00","guid":{"rendered":"https:\/\/www.root42.de\/blog\/?p=150"},"modified":"2010-04-11T11:49:00","modified_gmt":"2010-04-11T11:49:00","slug":"extremely-slow-smb-performance-over-wifi-using-os-x","status":"publish","type":"post","link":"https:\/\/www.root42.de\/blog\/?p=150","title":{"rendered":"Extremely slow SMB performance over WiFi using OS X"},"content":{"rendered":"<p>I have an OpenSUSE machine running a Samba server to provide files to my network. Now when I use the MacBook Pro to access those files, this happens awfully slow, with 80-200 KiB per second. I never figured out why, since rsync and sftp work very fast (for WiFi at least), at speeds of around 1.2 MiB per second. Today I googled for it, and it turns out that OS X delays ACK packages. I have no clue why it does that and what good this does, but you can disable it by running:<\/p>\n<div><\/div>\n<div><span style=\"white-space:pre\"><span  style=\"font-family:'courier new';\"> <\/span><\/span><span  style=\"font-family:'courier new';\">sudo sysctl -w net.inet.tcp.delayed_ack=0<\/span><\/div>\n<div><\/div>\n<div>After that, my SMB transfers jumped to 1 MiB per second, minimum. You can presumably make this change permanent by adding &#8220;net.inet.tcp.delayed_ack=0&#8221; to the file \/etc\/sysctl.conf. This will then be applied during system startup.<\/div>\n<div><\/div>\n<div><b>Update<\/b>: <a href=\"http:\/\/www.stuartcheshire.org\/papers\/NagleDelayedAck\/\">Here<\/a> is a nice explanation why the performance of OS X suffers sometimes, when using delayed ACK, and also why it might be useful in some cases.<\/div>\n","protected":false},"excerpt":{"rendered":"<p>I have an OpenSUSE machine running a Samba server to provide files to my network. Now when I use the MacBook Pro to access those files, this happens awfully slow, with 80-200 KiB per second. I never figured out why, since rsync and sftp work very fast (for WiFi at least), at speeds of around &hellip; <a href=\"https:\/\/www.root42.de\/blog\/?p=150\" class=\"more-link\">Continue reading<span class=\"screen-reader-text\"> &#8220;Extremely slow SMB performance over WiFi using OS X&#8221;<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[2,24,100],"tags":[],"_links":{"self":[{"href":"https:\/\/www.root42.de\/blog\/index.php?rest_route=\/wp\/v2\/posts\/150"}],"collection":[{"href":"https:\/\/www.root42.de\/blog\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.root42.de\/blog\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.root42.de\/blog\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.root42.de\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=150"}],"version-history":[{"count":0,"href":"https:\/\/www.root42.de\/blog\/index.php?rest_route=\/wp\/v2\/posts\/150\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.root42.de\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=150"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.root42.de\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=150"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.root42.de\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=150"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}