SSIS Dataflow - Working with Indexes

HI Guys,

I am inserting 7 million records into table2 from table (Table2 has two non clustered indexes on it.).

When I use an OLEDB Source(Table1) to an OLEDB Destination(Table2), the package takes about 4 hours, however if I use an Execute SQL task (INSERT INTO Table2 SELECT * FROM Table1) it runs in a few minutes.

If I remove the indexes from the table the OLEDB source to destination method only then takes a few minutes (but I then spend a few hours waiting for the indexes to be re created).

I guess my question is when the table has the indexes on, why does the Execute SQL task run so much quicker?

Thanks