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Path: euryale.cc.adfa.oz.au!newshost.anu.edu.au!harbinger.cc.monash.edu.au!nntp.coast.net!news-res.gsl.net!news.gsl.net!news.mathworks.com!newsfeed.internetmci.com!zdc!zdc-e!szdc-e!news From: "John S. Dyson" <toor@dyson.iquest.net> Newsgroups: comp.os.linux.networking,comp.unix.bsd.freebsd.misc Subject: Re: TCP latency Date: Sat, 13 Jul 1996 17:26:49 -0500 Organization: John S. Dyson's home machine Lines: 37 Message-ID: <31E822A9.41C67EA6@dyson.iquest.net> References: <4paedl$4bm@engnews2.Eng.Sun.COM> <31E106AF.41C67EA6@dyson.iquest.net> <4rvmtf$ven@linux.cs.Helsinki.FI> <31E3D9E2.41C67EA6@dyson.iquest.net> <4s5bl2$qpg@linux.cs.Helsinki.FI> <31E664EB.167EB0E7@inuxs.att.com> <4s9173$b8l@verdi.nethelp.no> NNTP-Posting-Host: dyson.iquest.net Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Mailer: Mozilla 3.0b5a (X11; I; FreeBSD 2.2-CURRENT i386) Xref: euryale.cc.adfa.oz.au comp.os.linux.networking:45129 comp.unix.bsd.freebsd.misc:23502 Steinar Haug wrote: > > Optimization FreeBSD Linux > -------------------------------------------- > 1 389 351 > 2 379 366 > 3 367 369 > > I also estimated standard deviation using the normal formula. It was in > the range 10-15 for all of the numbers above. > > And what does it mean? > > - On this particular machine, the measured versions of FreeBSD and Linux > are so close on the lat_tcp loopback test that I'm highly doubtful it > makes any difference at all in practice. > > - Linux was somewhat faster on the average for two of the optimization > levels, but given the estimated standard deviation I find it hard to > draw any conclusion from this. > > - The compilation options have *some* effect, but not necessarily what > you think. You need to actually try it out to draw sensible conclusions. > I see an improvement of about 5% on FreeBSD with these numbers, and that is about the same as the differences in the performance in the OSes. I agree that there are too many variables to conclude anything else considering the closeness of the results. I have worked on the FreeBSD VM stuff for a long time, it is AMAZING the differences that locality of reference and the TLB can cause. I SERIOUSLY appreciate the unbiased display of the results, and unbiased analysis. THANK YOU!!! John