# Integer Factorisation

Parallel versions of the ECM and MPQS integer factorisation algorithm are available since V2.27. One can simply use `SetNthreads(t);` to select $t$ threads on the local node, and optionally use `StartWorkers` to include workers on other nodes. Then integer factorisation will automatically use the parallel versions when the integers are large enough for the ECM or MPQS algorithms to be selected.

## `Example: Integer Factorisation (ex-1169a4)`

The following code factors 10 random 80-digit integers using 32 threads on the local manager node, and 32 threads on the worker node2.

```magma
> SetNthreads(32);
> StartWorkers("node2", 32); // start worker with 32 threads on node2
> SetVerbose("Factorization", 1);
> SetVerbose("MPQS",1);
> for i := 1 to 10 do
>     n := Random(10^80);
>     time Factorisation(n);
> end for;

```