Less terrible

A project log for Terrible Cluster

5 Raspberry PI Zeros. One custom USB hub. Endless disappointment.

ajlittajlitt 10/04/2017 at 04:072 Comments

Although performance is not the goal here, I wasn't happy that the cluster wasn't benching anywhere near what I expected with HPL.  After some head scratching, I found out that the math library that I used to build the benchmark (libatlas) is built for soft-float in the RPi repos.

I rebuilt HPL with the libopenblas math library, added the head node into the pool, and hooked up my bench supply so I can use its current meter.

Now the terrible cluster does a max of 1.281 GFLOPS, and drew an average of 4.962W over the run.  That means it's only 72 million times slower than the fastest computer on the June '17 Top500, and at an efficiency of .258 GFLOPS/W is 4.9 times more efficent than the least efficient computer in the same list.

(corrected with a slightly higher score after retesting 10/5/17)


Jarrett wrote 10/05/2017 at 23:41 point

I appreciate the convenience of a single HaD link I can send to people instead of explaining to every single person why trying to build a RasPi computer cluster is a terrible idea.

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ajlitt wrote 10/06/2017 at 01:47 point

Kids, don't try this at home.

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