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The current way to get a lot of efficient computation on a modern computer is to engage the GPU of said machine. This means that any language hosted on the CPU

by jlouis 6y ago

The current way to get a lot of efficient computation on a modern computer is to engage the GPU of said machine. This means that any language hosted on the CPU is going to be at a disadvantage. In short: you are better off writing a compiler toward the GPU and use it as a compilation target. And a lot of things argues that language benefits from being a functional one, given how GPUs tend to work on data. If there were no prior work, and if we have the full GPU specs, I'd reckon you want languages which are strong in program translation: Haskell or OCaml comes to mind. Elixir---as well as its Erlang sibling---are really good at handling problems where there is concurrency involved. It is subtly different from parallel computation in that you often have many threads of execution all wanting to do different things at the same time. It is the same space e.g., Go occupies really well.

Firadeoclus 6y ago
As someone who has been writing hand-optimised GPU code for a while now, I'd argue that this high level view (and thus an appropriate functional high-level language) can get you reasonably decent performance on a GPU for little effort for many highly parallel problems. And there are still plenty of cases where this will leave performance improvements of an order of magnitude on the table, because the compiler isn't smart enough to work out the optimal sequencing of operations. Often the computational core which benefits from running on a GPU is small and its complexity low enough that, if performance is a priority, you are better off writing it in an imperative low-level language as a library which can be accessed from higher level code.
- Munksgaard 6y ago
  Do you have any examples of such cases? I'm asking because I'm part of the team that's working on the Futhark language[0], which is exactly what you're describing: a high-level array language in a functional style, targeting the GPU. We're always on the lookout for interesting applications or benchmarks. In particular, we're interested in knowing exactly where our shortcomings are, compared to hand-written GPU code, so that we may work on improving them. For the curious, we think we're doing reasonably well compared to benchmark suites such as Rodinia[1], though there are still cases where we cannot keep up. [0]: https://futhark-lang.org/ https://futhark-lang.org/ [1]: https://futhark-lang.org/performance.html https://futhark-lang.org/performance.html
physicsyogi 6y ago
> The current way to get a lot of efficient computation on a modern computer is to engage the GPU of said machine. This means that any language hosted on the CPU is going to be at a disadvantage. That's only true if your calculations are mostly the kind of things that take advantage of GPUs, like working with deep neural nets or graphics. For most other things using multiple CPU cores will be better.

by jlouis 6y ago

Firadeoclus 6y ago

As someone who has been writing hand-optimised GPU code for a while now, I'd argue that this high level view (and thus an appropriate functional high-level language) can get you reasonably decent performance on a GPU for little effort for many highly parallel problems. And there are still plenty of cases where this will leave performance improvements of an order of magnitude on the table, because the compiler isn't smart enough to work out the optimal sequencing of operations. Often the computational core which benefits from running on a GPU is small and its complexity low enough that, if performance is a priority, you are better off writing it in an imperative low-level language as a library which can be accessed from higher level code.

Munksgaard 6y ago
Do you have any examples of such cases? I'm asking because I'm part of the team that's working on the Futhark language[0], which is exactly what you're describing: a high-level array language in a functional style, targeting the GPU. We're always on the lookout for interesting applications or benchmarks. In particular, we're interested in knowing exactly where our shortcomings are, compared to hand-written GPU code, so that we may work on improving them. For the curious, we think we're doing reasonably well compared to benchmark suites such as Rodinia[1], though there are still cases where we cannot keep up. [0]: https://futhark-lang.org/ https://futhark-lang.org/ [1]: https://futhark-lang.org/performance.html https://futhark-lang.org/performance.html

physicsyogi 6y ago

> The current way to get a lot of efficient computation on a modern computer is to engage the GPU of said machine. This means that any language hosted on the CPU is going to be at a disadvantage. That's only true if your calculations are mostly the kind of things that take advantage of GPUs, like working with deep neural nets or graphics. For most other things using multiple CPU cores will be better.