Date: Wed, 28 Nov 2001 18:35:48 +0000 From: John Vinters <johnv@jbg.co.uk> To: hackers@FreeBSD.ORG Subject: Re: FreeBSD performing worse than Linux? Message-ID: <3C052E84.3CF81084@jbg.co.uk> References: <bulk.69732.20011128081135@hub.freebsd.org>
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I've (reasonably) recently installed 4.3-Release on a system running Samba and a few light telnet apps, and noticed similar performance problems. The SMB sessions would randomly change speed, and telnet sessions would suffer from occasional "hesitation" (this is on a Dual PIII-700 MHz machine with 1 Gb of RAM, which is currently very lightly loaded). I managed to track the problem down to the duplex settings on both the Ethernet cards (AT-2500 TX, Realtek 8139 based, AFAIK) and the 10/100 Switch. Forcing both the cards and the switch to particular settings cured the problem, and lead to a massive performance increase. FTP seems to be particularly badly affected by the constant collisions (causing backoff). The problem can be tricky to find as the switch wasn't perceptably showing collisions on the collision LED, but viewing the switch stats showed a different story! I've noticed similar problems with Linux and certain cards (it was a while ago). John Vinters <johnv@jbg.co.uk> > Date: Wed, 28 Nov 2001 20:07:38 +1100 > From: "Chris Knight" <chris@aims.com.au> > Subject: RE: FreeBSD performing worse than Linux? > > Howdy, > > I had a similar problem, especially with different FreeBSD 4.x boxes (4.1.1, > 4.2, 4.3, 4.4-stable after dirpref merge) and with Windows NT systems, but > the crap performance was only limited to FTP. SSH, NFS and CVS operations > were all fine. The pre-4.3 boxes are all using RTL8029 cards, and the 4.3+ > boxes are all Intel 8255x-based cards. The laptop has 4.4-stable and a > D-Link DFE-650. The poor performance showed up in interactions with the > 100Mbit/s cards (Intel, D-Link). They have all disappeared since I've > explicitly set the links to 100Mbit/s with full-duplex. The switches and > hubs are all 10/100 D-Links. > My guess is that the autonegotiation feature of both the fxp and ed drivers > somehow adversely affects FTP. > However this is only surmise. My fix was based more on an inspired guess > than methodical practice and I didn't get the opportunity to delve deeper > into the reasons for the problem. Sometimes the real world can be a pain :-) > > Regards, > Chris Knight > Systems Administrator > AIMS Independent Computer Professionals > Tel: +61 3 6334 6664 Fax: +61 3 6331 7032 Mob: +61 419 528 795 > Web: http://www.aims.com.au > To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message
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