Filippo Mantovani: ARM for HPC

On 23-Oct-2017 Filippo Mantovani held a talk in Darmstadt on “Mobile technology for production-ready high-performance computing systems: The path of the Mont-Blanc project”. Unfortunately I was unable to attend, but Mr. Mantovani sent me his Darmstadt Seminar slides. As his slides and documents are very interesting to people using or intending to use ARM in HPC, I copy these documents here, so they are easily available. I also copied a report on “MB3_D6.4 Report on application tuning and optimization on ARM platform“.

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Hard-Disk and USB Drive Speed Comparisons

Continuing the post Harddisk Drive Speed in MB/s, here are some benchmarks for consumer grade hard disks, USB thumb drives, and solid state drives (SSD).

A 64 GB SanDisk USB 3.0 thumb drive:
img src="https://lh3.googleusercontent.com/-Qt4lveCJG_0/VJ7qg9phJ1I/AAAAAAAAR18/jihNvXB3fdE/w633-h599-no/Screenshot%2Bfrom%2B2014-12-27%2B18%3A12%3A02.png" alt="64 GB SanDisk Ultra USB thumb drive" /><a href="https://eklausmeier.files.wordpress.com/2015/06/screenshot-from-2014-12-27-18-12-02.png"><img src="https://eklausmeier.files.wordpress.com/2015/06/screenshot-from-2014-12-27-18-12-02.png" alt="Screenshot from 2014-12-27 18-12-02" width="633" height="599" class="aligncenter size-full wp-image-3025" /></a>

This USB drive has only half of the speed of the USB drive given below.

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Performance of Dalvik versus native C compilation

Android application programs are usually written in the Java programming language. Java source code is compiled to bytecode, which is then interpreted by the Java virtual machine. Current virtual machines (VM for short) use two tricks to improve performance:

  1. compile bytecode to machine code during run-time (JIT: just-in-time compilation)
  2. optimize machine code according usage pattern (hotspot technology)

Despite all these tricks native code produced by C/C++ compilers is ways faster than JIT/hotspot, see for example shootout from 2008, or see The Computer Language Benchmarks Game.

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