Return to BSD News archive
Path: euryale.cc.adfa.oz.au!newshost.anu.edu.au!harbinger.cc.monash.edu.au!news.rmit.EDU.AU!news.unimelb.EDU.AU!munnari.OZ.AU!spool.mu.edu!howland.reston.ans.net!tank.news.pipex.net!pipex!dispatch.news.demon.net!demon!sunsite.doc.ic.ac.uk!yama.mcc.ac.uk!news.salford.ac.uk!aber!not-for-mail From: pcg@aber.ac.uk (Piercarlo Grandi) Newsgroups: comp.os.linux.development.apps,comp.os.linux.development.system,comp.os.linux.hardware,comp.os.linux.setup,comp.os.linux.x,comp.unix.bsd.386bsd.misc,comp.unix.bsd.bsdi.misc,comp.unix.bsd.freebsd.misc,comp.unix.bsd.netbsd.misc Subject: Re: Sometimes you need X server source (Was: Why to not buy Matrox Millennium) Date: 31 Mar 1996 23:47:11 +0100 Organization: Prifysgol Cymru, Aberystwyth Lines: 29 Sender: pcg@osfb.aber.ac.uk Message-ID: <vwjd95s6ftc.fsf@osfb.aber.ac.uk> References: <4j21ph$crr@slappy.cs.utexas.edu> <4j36ev$prl@news.Informatik.Uni-Oldenburg.DE> <4ja099$r8k@ceylon.gte.com> <ragnaroek1996Mar28.063723.8733@news2.compulink.com> Reply-To: pcg@aber.ac.uk (Piercarlo Grandi) NNTP-Posting-Host: osfb.aber.ac.uk In-reply-to: jwalters@idirect.com's message of 28 Mar 96 11:37:23 GMT X-Newsreader: Gnus v5.0.15 Xref: euryale.cc.adfa.oz.au comp.os.linux.development.apps:13849 comp.os.linux.development.system:20279 comp.os.linux.hardware:34820 comp.os.linux.setup:47957 comp.os.linux.x:28004 comp.unix.bsd.386bsd.misc:365 comp.unix.bsd.bsdi.misc:2869 comp.unix.bsd.freebsd.misc:16272 comp.unix.bsd.netbsd.misc:2647 >>> On 28 Mar 96 11:37:23 GMT, jwalters@idirect.com (Jonathan Walters) >>> said: jwalters> On 26 Mar 1996 23:57:28 GMT, mbr@poitin.gte.com (Mark jwalters> Rosenthal) wrote: mbr> I sometimes run my X connection over a modem, and it's slower than mbr> I'd like. What does this have to do with whether or not to buy a mbr> Matrox Millennium card? Someday soon, I plan on rebuilding my X mbr> server to include the LBX (low bandwidth X) extension. jwalters> Is it a figment of my imagination or do most modems already jwalters> compress any data being transfered. That would make LBX a jwalters> waste of time. No, because modems only compress data; what you want to do with the X11 protocol is to compress the procotol itself, because it is highly redundant not in data but _structurally_. The reason is that each X11 packet is some dozen bytes long because it contains a lot of large header fields that contain almost the same information packet after packet, and often the data they carry is very little (for example when you type a key, it may happen that the packet contains several dozen bytes of headers and carries a single byte of data). The headers don't compress very well _as generic data_, but can compress rather better if a specific strategy (typically a variation on turning the X protocol from datagram to VC based) is used.