Is Multi-Threaded algorithm required to make use of Multi-core processors?

Question

I was just wondering whether we actually need the algorithm to be muti-threaded if it must make use of the multi-core processors or will the jvm make use of multiple core\'s eve

Answer 1

I don't believe any current, production JVM implementations perform automatic multi-threading. They may use other cores for garbage collection and some other housekeeping, but if your code is expressed sequentially it's difficult to automatically parallelize it and still keep the precise semantics.

There may be some experimental/research JVMs which try to parallelize areas of code which the JIT can spot as being embarrassingly parallel, but I haven't heard of anything like that for production systems. Even if the JIT did spot this sort of thing, it would probably be less effective than designing your code for parallelism in the first place. (Writing the code sequentially, you could easily end up making design decisions which would hamper automatic parallelism unintentionally.)