[K12OSN] Re: Server sizing in the real world

[David Trask]

Yes...it makes a HUGE difference.  If the server is only working at
100baseT it's not realizing its full potential.  Use this analogy.  Say
you have a room with 25 kids who need to exit that room....go out into the
hall and enter 25 seperate classrooms.  Through a standard sized door they
will exit one at a time or maybe two at a time and go to their repective
classrooms.  Now...take that same 25 kids and now have them exit through a
door the size of a garage door.  They can now exit the room maybe 10 at a
time and thus will get to their classrooms that much faster.  Although the
terminal is still 100baseT....the server being able to serve it's data at
full speed allows the bottleneck to shift downstream to the client and not
at the server.  A real world example is this:  When I used to run at only
100baseT my kids couldn't really run TuxType in the lab....3 or 4 kids
could play and after that it was unplayable due to the speed.  Once I
moved to gigabit....20 kids could play.  If all your users are doing is
running simple web browsers with no plugins...or stuff like that...then
100baseT will work....to a point.  Gigabit allows you to get closer to the
function of a stand-alone desktop.  My kids are able to run
Flash....Mplayer, Realvideo...etc. with no latency or slowdown.  Entire
classes can play GCompris, Childsplay, and Tuxpaint.  This is the beauty
of gigabit.  I anxiously await the day that the clients are gigabit
too...though I'm not sure there will be a huge advantage unless servers
get faster.  Oh...one last thing....you'll notice a huge difference with
OpenOffice loading.

"Support list for opensource software in schools." <k12osn at redhat.com> on
Thursday, October 13, 2005 at 5:09 AM +0000 wrote:
>On 10/13/05, William Fragakis <william at fragakis.com> wrote:
>[SNIP]
>> I second the suggestion to put gigabit between the server and client
>> switch. That made all the difference for us. 10/100 would absolutely
>> choke beyond 5-7 clients on heavy internet activity. The other
>[SNIP]
>
>I keep seeing this recommendation but if all that the ltsp network is
>handling screen re-fresh then where is the need for gig network?
>Typically the application will run on the server using server bus and
>only the display data is sent to the client (plus some admin
>overhead). I only see max ~8mbps data bandwidth usage with all 25
>users busy on internet. Typical bandwidth is way below more in the
>region of ~2mbps
>
>Second the internet connect I have is 515kbps DSL. How can this amount
>of data overawe 100mbps network?
>
>Any guru to do calculations and throw light on this?
>--
>Sudev Barar
>Learning Linux
>
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David N. Trask
Technology Teacher/Coordinator
Vassalboro Community School
dtrask at vcsvikings.org
(207)923-3100