[K12OSN] New Building's LTSP Server

[Jeff Siddall]

On 04/20/2011 09:55 AM, Joseph Bishay wrote:
> Hello everyone,
> 
> The feedback has helped tremendously with spec'ing out the new machine
> for us.  The key points so far that I have are:
> 
> 1) SATA RAID 1 drives for space, SSD for OS & /tmp
> 2) 16 GB RAM
> 3) three gigabit NICs (one to switch for computer lab, one for rest of
> school, plus a third for Internet access)
> 4) local-apps for firefox/OpenOffice to alleviate some load
> 
> The little shop I deal with has recommended the Intel Core i7-960
> 3.2ghz 8M Cache 4 Core CPU or the Intel Core i7-970 3.2ghz 12M Cache 6
> Core processors.  However the vast majority of online reading I've
> done says for "servers" or intensive-use applications (which I'd
> assume LTSP falls under!) you're better off with the new Xeon series
> of chips.

My experience has been that RAM, disk and network performance are all
far more important than CPU speed.  My relatively slow quad core server
runs at about 90% idle during busy hours but disk and network can get
tapped out, and of course all the spare RAM is used for cache.

That being said as with anything else the more you spend the more you
get.  Same is true for Xeons.  They are targeted at servers and thus
have optimizations like lots of cache.  However, there is a price
penalty for this so you need to decide what you can afford and if it is
a good use of your funds.

Have a look here for CPU benchmarks:

http://www.cpubenchmark.net/cpu_list.php

Those are useful to get an idea what you can expect.

The Core i7 970 you mention above is a nice CPU for sure, but at $580 it
is 285% more expensive than the $203 Phenom II 1090T but is only about
65% faster.  If you need the fastest thing money can but Intel is the
only thing you should consider.  Otherwise think about AMD.

One more thought: on a system with a large number of users I would tend
to go with more slower cores rather than fewer faster cores.  Occasional
runaway processes will essentially kill a core.  The more cores you have
the less likely it is anyone will see a big performance hit.

Jeff