The idea of improving runtime speed and benchmarking has really bifurcated into single threaded and parallel programming universes. Most platforms have O(10) cores now so it's an order of magnitude question, but exploiting that is a problem that few languages are helpful at. JVM is much better for that than JSVM though.

(But usually the much bigger speed problem is in the programming phase, better to optimize for programmer performance than runtime performance or risk not delivering anything due to time/money limitations)