The midfielder moved to the Stadium of Light in the close-season but has seen his new side struggle, with Sunderland sitting second-bottom in the Premier League table after 11 matches.
Paolo Di Canio – who signed Giaccherini – has since left the club with Poyet replacing him in charge, and the Italy international believes he has already made a positive impact.
|8/1||Sunderland are 8/1 with William Hill to finish bottom|
"We are playing differently under Mr Poyet," he told the Sunderland Echo. "We've changed the mentality among the players since he arrived.
"And now we are proving that we can play differently too and it's an advantage for us.
"I enjoy playing that way and I'm happy to play in this team."
Reports had linked the Italy international with a return to Serie A with Inter Milan, but he insists he is committed to the club.
"It’s a beautiful experience which I wanted," he told Radio Mana Sport.
"The English game remains physical and less tactical, but there is a lot less pressure around it.
"At this moment in time all I am thinking of is to do well with my English club, then we will see what happens."