[K12OSN] benchmarks and bandwidth

Petre Scheie petre at maltzen.net
Fri Apr 9 19:15:51 UTC 2004

Eight years ago or so, I recall seeing some study that showed that the CPU in 
most office PCs spent 80-90% of their cycles in an idle state.  As I used to 
explain to people, that's not surprising when you consider how many zillion 
milli-second cycles occur between each keystroke even as the user types away in 
a word processor, plus all the time when the user is on the phone, talking to 
people, etc.  People seemed to understand that.  Most of those idle cycles were 
just wasted.  They were heavily used when things like the computer was booting, 
programs were loading, recalculating, etc. but that was a small percent of the 
time.  They understood that, too.  That was back in the days of '300mhz 
screamers'.  Fast-forward eight years and in any given second on a PC there are 
likely to be ten times as many cpu cycles--but people still type at the same 
speed.  Granted, there's more going on in the complexity of the software, but 
processing words and so on hasn't changed much.  But the number of idle cpu 
cycles has jumped signficantly.  What a terminal server does is allow you to use 
those cycles among several people rather than just 'throw them away'.  The idea 
that everyone needs their own high-power PC is ridiculously wasteful.  And when 
you remind people of what they were doing eight years ago (adults, not kids), 
they seem to recognize that today's activities are not a whole lot more complex 
than back then, and perhaps this 'need get new hardware & software' cycle is a 
bit of a scam.  This also explains why, particularly in Unix/Linux, RAM is so 
much more important than CPU speed.

This isn't benchmark data that you can show people, but it does put it in terms 
they can relate to.


Huck wrote:
> Starting this on a seperate thread, so as not to "hijack" or something.
> (this is my first listserv experience, and quite helpful I might add)
> If those of you who operate a k12ltsp environment in a school setting
> could possibly post real results of what you have in those working 
> environments
> for those of us trying to convince admins to make the switch.
> a question I'm running into is:
> "You are trying to tell me that 1 computer, "(they can't really 
> differentiate between a server and a workstation)
> "will be able to run applications for this lab of 30 machines doing 
> multimedia applications "
> "like Cinelerra, The Gimp, or Open Office and web browsing?"
> and all I can say is "I think so, until I get the go ahead to TRY it and 
> find out"
> I guess what I need is some tangible evidence.
> Such as:  on server with 4gigs of ram running on scsi with a 800mhz fsb 
> and a 3.0 GHz cpu
> my server is handling 50 concurrent connections running various programs 
> from TuxMath to The Gimp
> and everything in between and is at 75% cpu load and 80% memory, and 
> never using swap space...
> and all clients are running smooth and clean.
> --Huck =)
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