Yuwen Shu
In 606, Emperor Yang revised the methods for promoting officials, requiring not only that they be competent but also show virtues and specific accomplishments before they could be promoted. He put seven officials in charge of the process of reviewing officials' performance and promotions—Su, along with Niu Hong, Yuwen Shu, Zhang Jin (), Yu Shiji, Pei Yun (), and Pei Ju, and they were known collectively as the "seven nobles of officialdom." However, although all seven consulted on the decisions, the main authority fell into the hands of Yu, and it was alleged that Yu decided the promotions based on the amounts of bribes he received.