Rhiannon has landed!! – The new IBM iDataPlex based Windows HPC benchmarking cluster is operational

We are excited to unveil the name for our new Windows HPC benchmarking cluster – Rhiannon:

 

 “Rhiannon. This stunning name has never cracked the U.S. top 500, despite the Fleetwood Mac song of this name that hit the charts in the 1970s. In Welsh mythology, Rhiannon was a horse goddess, and the name is derived from a phrase that means "great queen."

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

With 64 nodes/512 cores, our Rhiannon may not make another top500 neither, but we have decided to give the Top 500 Linpack testing a try using our HPC tool pack (aka, Lizard - Lizard helps you to determine the computational performance and efficiency that can be achieved by your HPC Pack 2008-based / Windows HPC Server 2008 cluster. It calculates and reports a peak performance value for your HPC cluster in billions of floating-point operations per second (GFLOPS), and a percentage value for the efficiency that was achieved at peak performance. After running Lizard, you can review the performance and efficiency results that were obtained, and optionally save these results and the parameters that were used to achieve them to a file on your computer.)

 

With single node, we are hitting 93% efficiency, or 83.1 Gflops out of 89.6 Gflops (2.8*4*8) peak performance!

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Now let’s try 256 cores and we are still getting 90%+ efficiency, or 2.59 Tflops out of 2.867 (2.8*4*8*32) Tlfops peak performance!  

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Two more data points since Rhiannon is based on the Intel Nehalem processor:

 

Turbo mode is on (2.66GHz -> 2.8GHz) and the Lizard actually took this into account automatically.  

One of Nehalem’s advantage is improved memory bandwidth. We’ve  also given Stream a try on the head node and here are the results:

 

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Function      Rate (MB/s)   Avg time     Min time     Max time

Copy:       38710.5347       0.0173       0.0165       0.0243

Scale:      38722.8032       0.0168       0.0165       0.0182

Add:        37164.4369       0.0269       0.0258       0.0393

Triad:      37180.2195       0.0270       0.0258       0.0398

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The numbers should speak for themselves. We look forward to get some HPC applications loaded and see where Rhiannon will take us!

 

Wenhao Wu

Sr. Technical Product Manager, Windows HPC Server