Read about bandwidth delay product: http://www.psc.edu/networking/projects/tcptune/
John On \!Thu, Feb 04, 2010 at 09:36:01PM +0100, Jean-Francois wrote: > Le jeudi 04 fivrier 2010 20:00:54, Sebastiano Pomata a icrit : > > If I may ask, I post to the list this question (I have no purpose on > > creating flames/trolls/os wars, just for my personal knowledge). > > > > On the same box (Core 2 Duo, Realtek Gigabit ethernet) I've performed > > today this simple test, downloading a big file from wu-wien FTP site > > (it's one of OpenBSD main mirrors). > > > > With a clean, partially configured default install of Linux Slackware > > (kernel 2.6.25) I reached download speeds of about 2.5 MB/s, while the > > same file from same server (not a round robin server for sure) > > downloaded on OpenBSD default 4.6 install hardly reached 400 KB/s. > > > > I repeated the test again two times, and got the same results. Then I > > fell over a page (https://calomel.org/network_performance.html) that > > offers some tweaking to OpenBSD's sysctl, and I dumbly pasted them in > > my sysctl.conf and rebooted. > > > > As (not) expected, download rate in OpenBSD reached almost exactly the > > same results of Linux Slackware. The main question is why? Do I need > > to tweak something more to get even better results? Are those settings > > safe enough to be used? Or the default settings had a strong reason > > for being there? > > Why on the FAQ (chapter 6) it says that tweaking > > net.inet.tcp.recvspace and > > net.inet.tcp.sendspace won't led to great improvements, while actually > > I got them? > > > > Again, my intentions are *really* positive and I just want to learn > > more (a quick search on -misc archives didn't led me to much stuff). > > > > Thank you > > Sebastiano > > > > In my opinion, the server limits the bandwith. I've had same issue. Reason why > you have 2.5 Mo is'nt clear, for me major openbsd ftp's are limited to approx > 400 Ko/sec per session. > Regards
