From owner-freebsd-current Wed Mar 15 16:58:25 2000 Delivered-To: freebsd-current@freebsd.org Received: from prism.flugsvamp.com (cb58709-a.mdsn1.wi.home.com [24.17.241.9]) by hub.freebsd.org (Postfix) with ESMTP id 6452E37C127; Wed, 15 Mar 2000 16:58:22 -0800 (PST) (envelope-from jlemon@flugsvamp.com) Received: (from jlemon@localhost) by prism.flugsvamp.com (8.9.3/8.9.3) id TAA41134; Wed, 15 Mar 2000 19:01:19 -0600 (CST) (envelope-from jlemon) Date: Wed, 15 Mar 2000 19:01:19 -0600 (CST) From: Jonathan Lemon Message-Id: <200003160101.TAA41134@prism.flugsvamp.com> To: msmith@FreeBSD.ORG, current@FreeBSD.ORG Subject: Re: Best NIC for FBSD (was: Buffer Problems and hangs in 4.0-CURRENT..) X-Newsgroups: local.mail.freebsd-current In-Reply-To: References: Organization: Cc: Sender: owner-freebsd-current@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG In article you write: >> In message <200003152053.MAA01346@mass.cdrom.com>, Mike Smith writes: >> >> fxp0: The Intel driver is by far the highest preformance model, >> >> beats the 3com (second best) hands down with much lower CPU >> >> overhead. >> > >> >Do you actually have any numbers to quantify this? There's nothing in >> >the driver architecture nor any of my testing that would suggest this is >> >actually the case at this point. >> >> The FreeBSD fxp driver does a lot to reduce the number of transmit >> interrupts; only 1/120 of transmitted packets result in interrupts. See >> the code relating to FXP_CXINT_THRESH. >> >> Assuming an even balance of transmitted and received packets, this should >> reduce the total number of interrupts by nearly 50%. I don't know if >> drivers for other cards do (or even can) use this approach. > >This is why I'm asking for real information here; so far all I'm hearing >is folklore. The xl driver, for example, does both transmit and receive >interrupt coalescing, which should make it superior again, right? 8( I've found that fxp and xl are roughly on a par for cpu overhead when under heavy http traffic, with xl holding a slight edge last time I looked. Of course, if you _really_ want to reduce cpu load, the Alteon cards (and the ti driver) beat both of them. -- Jonathan To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message