Date: Sun, 14 Mar 1999 01:27:49 -0800 From: Amancio Hasty <hasty@rah.star-gate.com> To: Matthew Dillon <dillon@apollo.backplane.com> Cc: Wes Peters <wes@softweyr.com>, Cory Kempf <ckempf@enigami.com>, Bill Paul <wpaul@skynet.ctr.columbia.edu>, freebsd-hackers@FreeBSD.ORG Subject: Re: Gigabit ethernet -- what am I doing wrong? Message-ID: <199903140927.BAA85633@rah.star-gate.com> In-Reply-To: Your message of "Sun, 14 Mar 1999 00:42:25 PST." <199903140842.AAA89134@apollo.backplane.com>
next in thread | previous in thread | raw e-mail | index | archive | help
> Most network cards must DMA into main memory -- card-to-card transfers > cannot be done. So routing a single packet requires the data to flow > over the PCI bus twice. The 132 MBytes/sec become 66 MBytes/sec right > off the bat. I am not sure that I can follow you here . Most PCI cards which are capable of doing dma to the host system's memory can do card - to - card transfer ;however, the target "card" most be able to use the stored data in the case of a network card it must have memory to receive the pack or a very elaborate protocol to accept short dma bursts which it can then process. Amancio To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?199903140927.BAA85633>