Fastest way to insert 1 million rows

Here is the fastest way to insert 1 million rows to a table in SQL Server

Credit goes this post: Generate and Insert 1 million rows into simple table

WITH
L0 AS (SELECT c FROM (SELECT 1 UNION ALL SELECT 1) AS D(c)), -- 2^1
L1 AS (SELECT 1 AS c FROM L0 AS A CROSS JOIN L0 AS B), -- 2^2
L2 AS (SELECT 1 AS c FROM L1 AS A CROSS JOIN L1 AS B), -- 2^4
L3 AS (SELECT 1 AS c FROM L2 AS A CROSS JOIN L2 AS B), -- 2^8
L4 AS (SELECT 1 AS c FROM L3 AS A CROSS JOIN L3 AS B), -- 2^16
L5 AS (SELECT 1 AS c FROM L4 AS A CROSS JOIN L4 AS B), -- 2^32
Nums AS (SELECT ROW_NUMBER() OVER(ORDER BY (SELECT NULL)) AS k FROM L5)

insert into yourtable
select k as IdColumn, 'whatever' as otherColumnName
from nums
where k <= 1000000