Actually, if I was concerned about scaling to a 20-core CPU[0], I probably wouldn't use anything mainstream. It depends on the exact problem, of course, but that sort of thing is generally easier in functional languages.
Many of the author's questions can be reduced to "does it have a good C FFI?", but I'm not sure what the overall point is, or if these are just generalized suggestions to think about before starting a project. I'd like to know what the author would use in this situation.
[0] AMD has announced a 12-core Opteron for next year, so this isn't far-fetched at all.
In my opinion, that would be a pretty poor decision. Most functional languages have not actually been tested on a 20 CPUs. You have no idea how optmized it will run there. You have no idea how it will scale.
You can't have strange hardware, and then decide to go with experimental software. Stateless programming can be done in any imperative language, and there are lots of languages that allow you to scale to 20 CPUs, but are very mainstream.
Parallel-Processing is not much easier in functional languages. But optimizing to place specific tasks on specific processors is much easier in low level languages. I'd say your design decision is wrong.
Many of the author's questions can be reduced to "does it have a good C FFI?", but I'm not sure what the overall point is, or if these are just generalized suggestions to think about before starting a project. I'd like to know what the author would use in this situation.
[0] AMD has announced a 12-core Opteron for next year, so this isn't far-fetched at all.