[K12OSN] benchmarks and bandwidth

Terrell Prude', Jr. microman at cmosnetworks.com
Sat Apr 10 02:21:35 UTC 2004

Here ya go, Huck.

The Server:

Dual Athlon 1700+ (1.47GHz)
80GB IDE hard disk
Gig-E fiber NIC (I use a single-NIC installation)

The clients (25 of 'em):

Pentium-166's (a few Pentium-233's)
3Com 3C905 NIC
S3 Trio64 video board

GNU/Linux will use up every last bit of DRAM that "top" shows that you 
have; this is by design, and yes, it is a good thing.  The reason for 
this is that the Linux kernel will do a lot of caching to improve 
performance.  I have yet to see less than 1GB DRAM used for caching.  
CPU usage occasionally jumps up to 100%, but it usually hovers around 
10-15% when the kids're all sitting at terminals.  The swap isn't even 
used; perhaps if I added another fifteen or twenty clients, it might 
start, or if the kids all simultaneously started making giant bitmaps in 
the GIMP (they don't).  The users run either KDE or GNOME, their choice, 
and they often switch between the two!

Note also that I just recently built a second server for my own use, and 
the server specs above are the same except that the CPUs are 1.2GHz 
Athlon MPs (Palominos).  This is because I found those chips on sale for 
$35 apiece.  My load testing with K12LTSP 3.1.2 shows that this server 
should be just as good as the one in production.  Again, DRAM is the 
key, followed immediately by Gig-E.  CPU power seems to be a-plenty.


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 =)
>K12OSN mailing list
>K12OSN at redhat.com
>For more info see <http://www.k12os.org>

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