Date: Thu, 01 Jun 2000 16:50:49 -0400 From: Dennis <dennis@etinc.com> To: Joy Ganguly <joy@niksun.com>, freebsd-hackers <freebsd-hackers@freeBSD.org> Subject: Re: S5933 PCI Adapter..?? Message-ID: <200006012051.QAA03632@etinc.com> In-Reply-To: <3936C677.C3C04A83@falcon.niksun.com> References: <Your message of "Thu, 01 Jun 2000 11:18:36 EDT."<200006011518.LAA02647@etinc.com> <200006011518.LAA02647@etinc.com> <Your message of "Fri, 26 May 2000 11:45:18 EDT." <392E9C0E.4B9EB0FB@falcon.niksun.com> <200006011829.OAA03264@etinc.com>
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At 04:24 PM 6/1/00 -0400, Joy Ganguly wrote: >Dennis wrote: > >> At 12:13 PM 6/1/00 -0600, Warner Losh wrote: >> >In message <200006011518.LAA02647@etinc.com> Dennis writes: >> >: Have you done bus performance testing with this card? Given the >> >: architechture of the AMCC part, it seems highly improbable that you will be >> >: able to get high throughput with such a card. Because the AMCC part >> >: requires external logic it is impossible to do pass-through single cycle >> >: bursts, which is required for efficient utilization of the PCI bus. Once >> >: you begin holding off cycles the PCI bus totally pigs out (which is why >> >: virtually all high-speed pci solutions are single-chip type designs). >> > >> >Yes. I've done drivers for several cards with this design. The AMCC >> >part is very fussy and will often lock up the bus unless the card >> >designer has put enough extra logic on the card to cope with the >> >oddities of the card. Sadly, many don't. >> >> We used it on our first (and now defunct) pci board, and we didnt have >> trouble with lockups (there are quite a few errata that have to be >> addresses), but the arbitration was pitifully slow. There was no way to get >> high throughput across the bus. We completely rejected it for use on >> T3...i find it interesting that someone did an OC3/ATM card with it. >> >> Dennis >> >> Emerging Technologies, Inc. >> > >well the problem seems to have been with the motherboard. i changed the >motherboard and the card is working. >we are using "point" oc3 card from 'applied telecom'. we have not done >any >performance testing. the card is mainly meant for monitoring. of course this discussion has nothing to do with your problem...but Im glad you figured it out :-) good luck with your throughput. DB To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message
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