You can't change the voltage on states P0-P5 on the core or P0-P3 on the Memory without modifying the registry. In essence the tables don't give you any extra hashrate but lower the amperage draw of the card. You can save like 60W per card.

Most people don't understand that. They simply open AMD settings and bring the power settings down -20% and think they are running at max efficiency.. which they are absolutely not. Not even close.