[Beowulf] 96 Processors Under Your Desktop (fwd from brian-slashdotnews@hyperreal.org)

[Glen Gardner]

I have been touting the virtues of low power use clusters for the last 
year. I hope to build a second one next year , with twice the 
performance of the present machine.
My experience with my low power cluster has been that it is not a "big 
iron" machine, but is very effective, and very fast for some things. 
Also, a low power use cluster is the only way I can have a significant 
cluster in my apartment, so it was to be this way, or no way. At 
present, the cost of power for my 14 node cluster is running about $20 a 
month (14 nodes up 24/7 and in use much of the time).

It is rather difficult to operate a significant opteron cluster in an 
office environment (or in an efficiency apartment). The heat alone will 
prevent it. If you need lots of nodes and low power use, the "small p 
performance" machines are going to be the way to go.  I can think of 
many situations where it would be desirable to have a deskside cluster 
for computation, development, or testing, and the low power machines 
opens the door to a lot of users who can't otherwise take advantage of 
parallel processing.
A 450 watt , 10 GFLP parallel computing machine for about $10K seems 
attractive. It is even more attractive if it does not need any special 
power or cooling arrangements.


Glen


Mark Hahn wrote:

>>Transmeta 2) This is not shared memory setup, but ethernet connected. So
>>    
>>
>
>yeah, just gigabit.  that surprised me a bit, since I'd expect a trendy
>product like this to want to be buzzword-compliant with IB.
>
>  
>
>>Does anyone have any idea haw the Efficeon's stack up against Opterons?
>>    
>>
>
>the numbers they give are 3Gflops (peak/theoretical) per CPU.
>that's versus 4.8 for an opteron x50, or 10 gflops for a ppc970/2.5.
>they mention 150 Gflops via linpack, which is about right, given
>a 50% linpack "yield" as expected from a gigabit network.
>
>remember that memory capacity and bandwidth are also low for a typical
>HPC cluster.  perhaps cache-friendly things like sequence-oriented bio stuff
>would find this attractive, or montecarlo stuff that uses small models.
>
>  
>
>>A quad cpu opteron comes in at a similar price as Orion's 12 cpu unit,
>>but the opeteon is a faster chips and has shared mem. The Orion DT-12
>>lists a 16 Gflop linpack. Does anyone have quad Opteron linpack results?
>>    
>>
>
>for a fast-net cluster, linpack=.65*peak.  for vector machines, it's closer 
>to 1.0; for gigabit .5 is not bad.  for a quad, I'd expect a yield better 
>than a cluster, but not nearly as good as a vector-super.  guess .8*2.4*2*4=
>.8*2.4*2*4=15 Gflops.
>
>(the transmeta chip apparently does 2 flops/cycle like p4/k8, unlike 
>the 4/cycle for ia64 and ppc.)
>
>I think the main appeal of this machine is tidiness/integration/support.
>I don't see any justification for putting one beside your desk - 
>are there *any* desktop<=>cluster apps that need more than a single 
>gigabit link?
>
>for comparison, 18 Xserves would deliver the same gflops, dissipate
>2-3x as much power, take up about twice the space.
>
>personally, I think more chicks would dig a stack of Xserves ;)
>
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>  
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-- 
Glen E. Gardner, Jr.
AA8C
AMSAT MEMBER 10593



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