From mboxrd@z Thu Jan 1 00:00:00 1970 From: wolfgang.rostek@gmx.de (Wolfgang Rostek) Date: Fri, 3 Apr 2015 17:34:44 +0200 Subject: [lttng-dev] major variations in perfomance figures In-Reply-To: References: , Message-ID: ... > > Frequence scaling I can't imagine on my dektop machine. > > It is a jump between 350ns and 800ns. In the loop below > > all the events of one test run are of equal time distance, > > either slow or fast. > > Frequency scaling can still definitely play a role, even on a desktop machine. > Also, Core i5 chips support Turbo Boost which should be disabled to > perform benchmarks. > > I'm guessing you get your time measurements from the timestamps in the > trace? Yes I'm not hunting for a detailed benchmark. Only such a large variance makes me thoughtful. For such a test I did expect some 10-30% but not this more than 200%. Wolfgang R.