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This is the key aspect of actual HPC clusters that appears to be missing from the pretenders. That completely depends on your workload. For example, we did (na

This is the key aspect of actual HPC clusters that appears to be missing from the pretenders. That completely depends on your workload. For example, we did (natural language) parsing on thousands of CPUs on one of the large European computation grids. This work was largely CPU bound, the input and output data is relatively small, so the interconnect speed is not a big factor. The problem is embarrassingly parallel, so the primary consideration is having enough CPUs with a reasonable amount of memory.

gnufx 8y ago
When we say "HPC" generally, we're talking about being able to run computation that isn't embarrassingly parallel. The bulk of work on typical general purpose systems tends to be DFT-type materials science and finite element/CFD engineering. Obviously if you have a special purpose system you can made different trades-off.
- mmt 8y ago
  To be fair, you original comment did use both "supercomputer" and "HPC". I'd argue that, although in most people's minds, the two are indistinguishable (perhaps like the words "envious" and "jealous"), but carry a unique significance to practitioners. That said, any lay definition of supercomputer would seem to require actual performance (e.g. high FLOPS rate), which trivally supports the initial assertion. One can call something like the Folding@Home project a distributed supercomputer, but it's not that interesting, especially to build such a system, for anything embarrassingly parallel.
- danieldk 8y ago
  To many practitioners (people using HPC rather than people designing HPC), HPC means an aggregation of computing resources to deliver orders of magnitude of higher performance than one could get from a single workstation. Obviously if you have a special purpose system you can made different trades-off. It should be obvious, but the post I was reacting to was claiming that it cannot be 'real HPC' without high-speed interconnects. It depends on what you are a cluster/HPC facilities for. Typically institutions (such as universities) have different facilities with different trade-offs.
  - mmt 8y ago
    > HPC means an aggregation of computing resources to deliver orders of magnitude of higher performance than one could get from a single workstation. > the post I was reacting to was claiming that it cannot be 'real HPC' without high-speed interconnects That was me, and that's still my point. The perception of users that have the embarassingly parallel workload isn't particularly meaningful. We already had the pretty generic terms "grid computing", "distributed computing" and "cluster". What's the point of nomenclature like "HPC" if it describes something that's indistinguishable from that single workstation merely multiplied by some large number, somehow attached over the Internet? If it's not "real HPC", then what is a better term of art to describe the sort of computing that can deliver high performance to workloads that include ones that are not embarrassingly parallel?

gnufx 8y ago

When we say "HPC" generally, we're talking about being able to run computation that isn't embarrassingly parallel. The bulk of work on typical general purpose systems tends to be DFT-type materials science and finite element/CFD engineering. Obviously if you have a special purpose system you can made different trades-off.

mmt 8y ago
To be fair, you original comment did use both "supercomputer" and "HPC". I'd argue that, although in most people's minds, the two are indistinguishable (perhaps like the words "envious" and "jealous"), but carry a unique significance to practitioners. That said, any lay definition of supercomputer would seem to require actual performance (e.g. high FLOPS rate), which trivally supports the initial assertion. One can call something like the Folding@Home project a distributed supercomputer, but it's not that interesting, especially to build such a system, for anything embarrassingly parallel.
danieldk 8y ago
To many practitioners (people using HPC rather than people designing HPC), HPC means an aggregation of computing resources to deliver orders of magnitude of higher performance than one could get from a single workstation. Obviously if you have a special purpose system you can made different trades-off. It should be obvious, but the post I was reacting to was claiming that it cannot be 'real HPC' without high-speed interconnects. It depends on what you are a cluster/HPC facilities for. Typically institutions (such as universities) have different facilities with different trade-offs.
- mmt 8y ago
  > HPC means an aggregation of computing resources to deliver orders of magnitude of higher performance than one could get from a single workstation. > the post I was reacting to was claiming that it cannot be 'real HPC' without high-speed interconnects That was me, and that's still my point. The perception of users that have the embarassingly parallel workload isn't particularly meaningful. We already had the pretty generic terms "grid computing", "distributed computing" and "cluster". What's the point of nomenclature like "HPC" if it describes something that's indistinguishable from that single workstation merely multiplied by some large number, somehow attached over the Internet? If it's not "real HPC", then what is a better term of art to describe the sort of computing that can deliver high performance to workloads that include ones that are not embarrassingly parallel?