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Newsgroups: comp.os.386bsd.questions Path: sserve!newshost.anu.edu.au!munnari.oz.au!uunet!emba-news.uvm.edu!sadye.emba.uvm.edu!wollman From: wollman@sadye.emba.uvm.edu (Garrett Wollman) Subject: Re: Ethernet [really TCP] performance measurement Message-ID: <1993Jun13.202515.21826@uvm.edu> Sender: news@uvm.edu Organization: University of Vermont, EMBA Computer Facility References: <hastyC8KHzx.IAv@netcom.com> <1993Jun13.183538.19881@uvm.edu> <hastyC8KsH7.719@netcom.com> Date: Sun, 13 Jun 1993 20:25:15 GMT Lines: 38 In article <hastyC8KsH7.719@netcom.com> hasty@netcom.com (Amancio Hasty Jr) writes: >I am curious about your system configuration your ethernet performance >seems a bit on the low side. You're probably comparing it with a 16-bit Ethernet adapter that has a reasonable amount of memory. Me no got. The AT&T EN100 is an 8-bit adapter (i.e., SLOW SLOW SLOW) with only 16k of memory. (I am certain that I could handle 16k TCP windows if only I had 64k of memory...) In addition to the speed hit that I take from the slow adapter, my system itself is a 386/20 with no special speed enhancements (it predates all that by about four years). Here's what I get on the loopback (it might be better by now; I'm not sure how long ago this was done): ttcp-r: rcvbuf ttcp-r: accept from 127.0.0.1 ttcp-r: buflen=8192, nbuf=2048, align=16384/0, port=5001, sockbufsize=32768 tcp ttcp-r: 16777216 bytes in 109.09 real seconds = 150.19 KB/sec +++ ttcp-r: 16777216 bytes in 94.63 CPU seconds = 173.14 KB/cpu sec ttcp-r: 2053 I/O calls, msec/call = 54.41, calls/sec = 18.82 ttcp-r: 0.0user 94.5sys 1:49real 86% 0i+0d 0maxrss 0+0pf 2+1917csw ttcp-r: buffer address 0xc000 I've got the rudiments of a page-flipping implementation for the transmit side which should speed things up a little bit, but it won't help for the receive side. (Or at least, not until I figure out what the Right Way of doing it is.) Currently all I have is iovflipin(); I don't even know if this works because I never got around to testing it. (I think I got around to fixing the mbuf macros not to assume that everything with an M_EXT necessarily has a cluster allocated...) -GAWollman -- Garrett A. Wollman | Shashish is simple, it's discreet, it's brief. ... wollman@emba.uvm.edu | Shashish is the bonding of hearts in spite of distance. uvm-gen!wollman | It is a bond more powerful than absence. We like people UVM disagrees. | who like Shashish. - Claude McKenzie + Florent Vollant