From owner-freebsd-hackers Fri Nov 30 2:22: 7 2001 Delivered-To: freebsd-hackers@freebsd.org Received: from apollo.backplane.com (apollo.backplane.com [216.240.41.2]) by hub.freebsd.org (Postfix) with ESMTP id 5DE2C37B419 for ; Fri, 30 Nov 2001 02:22:05 -0800 (PST) Received: (from dillon@localhost) by apollo.backplane.com (8.11.6/8.9.1) id fAUAM1U09317; Fri, 30 Nov 2001 02:22:01 -0800 (PST) (envelope-from dillon) Date: Fri, 30 Nov 2001 02:22:01 -0800 (PST) From: Matthew Dillon Message-Id: <200111301022.fAUAM1U09317@apollo.backplane.com> To: John Vinters Cc: hackers@FreeBSD.ORG Subject: Re: FreeBSD performing worse than Linux? References: <3C052E84.3CF81084@jbg.co.uk> Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG :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! It probably wasn't collision backoff. It was probably packet loss due to the switch and the host getting confused over the duplex setting. i.e. where the switch thought it was one thing and the host thought it was another. The usual solution to this sort of switch/host confusion is to turn off autonegotiation on both sides and hardwire the duplex to full. On both sides. I've occassionally had similar problems (not in the last year or two, though... but definitely with older cards and switches). -Matt :I've noticed similar problems with Linux and certain cards (it was a :while ago). : :John Vinters : To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message