From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-lb0-f174.google.com ([209.85.217.174]:41882 "EHLO mail-lb0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751459Ab2DSHbv (ORCPT ); Thu, 19 Apr 2012 03:31:51 -0400 Received: by lbom4 with SMTP id m4so2872325lbo.19 for ; Thu, 19 Apr 2012 00:31:50 -0700 (PDT) Message-ID: <4F8FBF66.9050109@gmail.com> Date: Thu, 19 Apr 2012 09:31:50 +0200 From: Hoppetauet MIME-Version: 1.0 Subject: High standard deviation Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: fio-owner@vger.kernel.org List-Id: fio@vger.kernel.org To: fio@vger.kernel.org Hello Can someone give some insight as to why the standard deviation for completion latencies is so high? I have a completion latency avg of 0.21ms, while the st dev is 12.33ms. Is it because of some really high numbers here and there? Also, can someone tell me where the total latency is located in this --minimal output work;0;0;8388608;55741;154103;0;0;0.000000;0.000000;1;1323005;69.848293;1088.205315;0;60512;104.688135%;56986.986348;4117.299600;0;0;0;0;0;0.000000;0.000000;0;0;0.000000;0.000000;0;0;0.000000%;0.000000;0.000000;1.109655%;3.491194%;32878;0;33;100.0%;0.0%;0.0%;0.0%;0.0%;0.0%;0.0%;53.89%;44.49%;0.05%;0.01%;0.01%;0.01%;0.00%;0.01%;0.00%;0.01%;0.01%;0.84%;0.72%;0.01%;0.01%;0.01%;0.00%;0.01%;0.00%;0.00%;0.01%;0.00% Thanks