Date: Wed, 15 Mar 2000 19:01:19 -0600 (CST) From: Jonathan Lemon <jlemon@flugsvamp.com> To: msmith@FreeBSD.ORG, current@FreeBSD.ORG Subject: Re: Best NIC for FBSD (was: Buffer Problems and hangs in 4.0-CURRENT..) Message-ID: <200003160101.TAA41134@prism.flugsvamp.com> In-Reply-To: <local.mail.freebsd-current/200003160043.QAA03579@mass.cdrom.com> References: <local.mail.freebsd-current/200003152313.aa85970@salmon.maths.tcd.ie>
next in thread | previous in thread | raw e-mail | index | archive | help
In article <local.mail.freebsd-current/200003160043.QAA03579@mass.cdrom.com> 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
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?200003160101.TAA41134>