Subj : Re: kermit protocol in syncterm
To   : Digital Man
From : fusion
Date : Sat Aug 19 2023 02:28:00

On 18 Aug 2023, Digital Man said the following...
 
 DM> Correct, I'm talking about the protocol itself. Unless you're using a
 DM> compression feature with Kermit (are you?), it's really impossible for
 DM> the Kermit *protocol* to outperfrom Ymodem-G protocol over the same

no compression. i poked around on another machine for more testing.. built sexyz from http://synchro.net/Synchronet/sbbs_src.tgz and used it on my linux 'router' (i5-3550) to transfer a 700meg movie to my main machine with syncterm and then with ZOC via kermit and it turned out maybe closer to what you'd expect:

sexyz   zmodem:   ~6+MB/s   (~95% cpu)
sexyz   ymodem-g: <4.5MB/s  (~95% cpu)
gkermit kermit:   ~3.7MB/s  ( 11% cpu)

so that's a wash. zmodem still won though, so that's two of my machines that behaved that way.

this though:

lrzsz   zmodem:   ~55MB/s to ZOC and ~36MB/s to syncterm. (50% cpu)

is crazy.. syncterm did manage to receive from lrzsz at ~66MB/s with ymodem-g, but i had no successful transfers with it.

so yeah, ymodem-g is better, but which machines are you getting this performance from using sexyz? does anyone else? and what's it doing with all those cpu cycles?

 DM> Your "real life" test is over a localhost link or a local network? Why
 DM> on earth would you be using a serial/modem file transfer protocol over a
 DM> local network (Ethernet, WiFi?) and call that "real life"?

there isn't a significant difference between over the local network and the internet anymore. why shouldn't i be able to fetch a movie off a bbs via zmodem @ 55MB/s? many people with VPSes or that have fiber at home have that capability.

--- Mystic BBS v1.12 A47 2021/12/25 (Windows/32)
 # Origin: cold fusion - cfbbs.net - grand rapids, mi
 * Origin: Vertrauen - [vert/cvs/bbs].synchro.net (1:103/705)

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