Table schema:
CREATE TABLE table_name_71 (voltage VARCHAR, turbo VARCHAR, cores VARCHAR, release_date VARCHAR)

Question: What is the voltage when there are 2 cores, turbo is 5/8 and the release date is September 2010?
SQL: SELECT voltage FROM table_name_71 WHERE cores = "2" AND release_date = "september 2010" AND turbo = "5/8"