From C++14 and Java 1.8

[dsimcha]

On Sunday, 21 April 2013 at 13:30:32 UTC, bearophile wrote:
> dsimcha:
>
>> I abandoned because I was disappointed at how poorly most of 
>> it was scaling in practice, probably due to memory bandwidth.
>
> Then do you know why the Java version seems to be advantageous 
> (with four cores)?
>
> Bye,
> bearophile

I don't know Java very well, but possiblities include:

1.  Sorting using a virtual or otherwise non-inlined comparison 
function.  This makes the sorting require much more CPU time but 
not a lot more memory bandwidth.  It does beg the question, 
though, of why the comparison function isn't inlined, especially 
since modern JITs can sometimes inline virtual functions.

2.  Different hardware than I tested on, maybe with better memory 
bandwidth.

3.  Expensive comparison functions.  I didn't test this in D 
either because I couldn't think of a good use case.  I tested the 
D parallel sort using small primitive types (ints and floats and 
stuff).