From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Message-ID: <50605FEF.5020103@cran.org.uk> Date: Mon, 24 Sep 2012 14:28:15 +0100 From: Bruce Cran MIME-Version: 1.0 Subject: Re: FIO 2.0.9 for Windows Server 2008 RC1 SP2 reports extreme latencies References: In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit To: "Jeffrey McVay (jmcvay)" Cc: "fio@vger.kernel.org" , Jens Axboe List-ID: On 24/09/2012 06:41, Jeffrey McVay (jmcvay) wrote: > > On windows runing 4kB random Writes to a ramdisk with numjobs=4 and > iodepth=64 FIO reports clat and lat maximums times that match the > runtime of the test. Changing the numjobs=1 and iodepth=1 yields max > latencies that meet expectations. As a further sanity test I ran > similar workloads using IOMeter with max response times that were in > line with expectations. > > To reproduce: > > 1.Download and install the freeware version of Dataram ramdisk from > http://memory.dataram.com/products-and-services/software/ramdisk > > 2.Run FIO 2.0.9 with PhysD1_Fio_4kRandWr_4x64 > > 3.Notice the max entries for clat and lat > > 4.For comparison run FIO with PhysD1_Fio4kRandWr_1x1 > > Attached are the FIO jobfiles, latency logs for the two FIO runs, > IOMeter ICF files, IOMeter csv files, and screenshots comparing > similar runs of FIO and IOMeter. > Thanks. I've replicated the problem and will work out what's going wrong. -- Bruce Cran