speed churned non-static assignment t-sql

imagine i have brick initialisation formula during tip stored way array non-static assignments:

set @proc = 'sp_madeupname'
set @magic_number = 42
set @tomorrows_date = dateadd(dd, 1, getdate())
...

clearly doing above name faster:

select
     @proc = 'sp_madeupname'
    ,@magic_number = 42
    ,@tomorrows_date = dateadd(dd, 1, getdate())
...

but how much faster? contend stored way executed biased loop, several thousand times, going any touching inadequacy performance?