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From: rdippold@maui.qualcomm.com (Ron Dippold)
Newsgroups: comp.os.msdos.misc
Subject: Re: relative speeds of file transfer protocols wanted
Message-ID: <1991Feb27.064855.20296@qualcomm.com>
Date: 27 Feb 91 06:48:55 GMT
References: <27c66ffc@ralf>
Sender: news@qualcomm.com
Organization: Qualcomm, Inc., San Diego, CA
Lines: 31

In article <27c66ffc@ralf> Ralf.Brown@B.GP.CS.CMU.EDU writes:
>In article <1991Feb20.221117.13560@qualcomm.com>, rdippold@maui.qualcomm.com (Ron Dippold) wrote:
>}In article <1991Feb20.040652.26925@cs.cmu.edu> ralf+@cs.cmu.edu (Ralf Brown) writes:
>}>In article <1991Feb18.203344.1433@qualcomm.com> rdippold@maui.qualcomm.com (Ron Dippold) writes:
>}>}In article <1991Feb11.133727.1160@minyos.xx.rmit.oz.au> s902114@minyos.xx.rmit.oz.au (Zen) writes:
>}>}
>}>}   HyperP -   300 cps   (ZIPped file)
>}>
>}>Is that speed figure by the wall clock or using the built-in speed display?
>}
>}No, believe it or not, that ZIP file consisted of only 10 files and was about
>}200K long.  I timed it by the wall clock and by its internal display.  It did
>}slightly inflate the cps (it claimed 310 cps).  But with every ZIPped file I
>}have sent with HyperP, I get a 280 to 310 cps throughput!  That is what
>
>Since the docs state that compression is disabled on already-compressed files,
>here is my conjecture:	HyperP switches the modems into synchronous mode,
>thus using only 8 bits per character instead of 10.  This yields a raw
>throughput of 300cps, less any protocol overhead (MNP4/5 use about 15 cps,
>which is why Ymodem-G gets about 283/284 cps after subtracting its own small
>overhead).
>
>Have you tried HyperP on an MNP link or with compression turned off?  If my
>conjecture is correct, it will fail on an MNP link and show little or no
>speed difference with compression off (on ZIP files, that is).

Well, when I was testing it, I was running it on a 2400 bps modem without
MNP4 or 5 capability.  Now I've acquired a USR DS (evil laugh), so I'll have to
try it to see what it does when the USR is in maximum speed mode.  I'd play
around with it more, but it freezes so often on synchronization that it's
probably not worth it.