[dap]

That thread pool isn't actually that simple. How many threads do you use? If you throw 1,000 threads at the problem with a 2MB stack each, that's 2GB of DRAM you've thrown away (instead of 20MB * ncores per Node process) -- DRAM that could be caching filesystem data, for example, which could have a huge impact on overall performance.

With Node, the DRAM and CPU used scales with the number of cores and actual workload. With a thread pool, the DRAM used scales at least with the number of concurrent requests you want to be able to handle, which is often much larger than you can handle simultaneously (because many of them will be blocked much of the time).

Assuming you're not willing to reserve all that memory up front, the algorithm for managing the pool size also has to be able to scale quickly up and down (with low latency, that is) without thrashing.

[damageboy]

What a load of crap... you just wasted 2gb of address space not of DRAM... You'll "waste" exactly up to the amount of stack each thread uses, rounded up to PAGE_SIZE which is usually 4kb

Let me guess, a nodejs fan?

[dap]

You're right -- it's the touched pages that count. In many cases, that's a few MB per stack, which is what I said.