How to improve INSERT...SELECT * FROM table - 70GB data

using Vertica 9.0, 8 nodes, 170GB in general pool each node

the following statement inserts 70GB worth of data (compressed) for 100 mins. Can this still be improved to 30 mins?

INSERT /+direct/ INTO mytable SELECT * FROM anothertable;

I can't use COPY_TABLE because the table projections are different and will always be different because of the process logic.