Trivially parallelizable algorithms are definitely in the "not generally applicable" regime. But you're right, they're capable of hitting arbitrarily large, hardware-dependent speedups. And that's definitely something a sufficiently intelligent compiler should be able to capture through dependency analysis.

Note that I don't doubt the 35k speedup -- I've seen speedups into the millions -- I'm just saying there's no way that can be a representative speedup that users should expect to see.