You could speed up the loop by retrieving the size of the seedpoints container only once before the actual loop. Currently, you query the value in every iteration. You're also using post-increment insted of pre-increment (also for progress below), which will generate other unnecessary temporary variables. You can prevent all of this stuff by using range-based for. This would make writing and reading the code more simple as well.

Do you really want to output something on the console in a critical parallel loop? That's like driving a super sports car in first gear only. :-)