Xref: utzoo comp.dcom.modems:2513 comp.mail.uucp:1943
Newsgroups: comp.dcom.modems,comp.mail.uucp
Path: utzoo!henry
From: henry@utzoo.uucp (Henry Spencer)
Subject: Re: UUCP g stats
Message-ID: <1988Sep25.015301.768@utzoo.uucp>
Organization: U of Toronto Zoology
References: <183@arnold.UUCP> <1988Sep20.184054.2403@utzoo.uucp> <184@arnold.UUCP>
Date: Sun, 25 Sep 88 01:53:01 GMT

In article <184@arnold.UUCP> dave@arnold.UUCP (Dave Arnold) writes:
>> ... Uucp-g can run a line at circa 90%
>> of line speed quite consistently if the machines are fast enough and
>> the serial interfaces are not so stupid as to be a bottleneck...
>
>...I have never seen 90% bandwidth utilization.  My 3B1 at home running
>at 1200 baud always gets around 100-120 cps.  How are you computing
>bandwidth utilization?   ...   (c * 8) / b  ?

You're forgetting the start and stop bits.  It's 10 bits per character,
not 8.  90% of 1200 baud is 108 cps.  Back when most of our news traffic
was at 1200, we saw uucp running at 109 +- 2 or so cps for hours on end,
quite consistently, for most sites.  At 2400 the loading on the machines
starts to matter a bit more, so the variation increased, but the numbers
were still pretty consistent.  At higher speeds, system loading and
various kinds of hardware brain-damage matter a lot more, the rates
vary all over the place, and 90% becomes the "guaranteed not to exceed"
utilization rather than the average.
-- 
NASA is into artificial        |     Henry Spencer at U of Toronto Zoology
stupidity.  - Jerry Pournelle  | uunet!attcan!utzoo!henry henry@zoo.toronto.edu