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