.Q.fc[x;y]

Where

returns the result of evaluating f vec – using multiple threads if possible. (Since V2.6)

q -s 8
q)f:{2 xexp x}
q)vec:til 100000
q)\t f vec
12
q)\t .Q.fc[f]vec
6

In this case the overhead of creating threads in peach significantly outweighs the computational benefit of parallel execution.

q)\t f peach vec
45