Thanks for the great post!  On my machine (two Intel Xeon E5335 @ 2 GHz with 4 GB of RAM, i.e. 8 cores) this takes 2256 ms.

The single threaded version takes 17470 ms.

 

The first set of code works:

 

// par : Async<array<int * bool>>

let par = Async.Parallel info

// primeInfo : array<int * bool>

let primeInfo = Async.Run par

 

The second does not:

 

let primeInfo = nums

|> Array.map (fun x -> async { return (x, IsPrime x) } )

|> Async.Parallel

|> Async.Run

 

I get an error on "Aysnc.Run":

 

This expression has type  'a * 'b but is here used with type  Async<(int * bool) array

 

Any ideas?

 

Thanks,

Dan