The French defender joined the Black Cats from Lorient in the January transfer window, and he has impressed hugely in his first two matches for the Wearsiders.
Kone produced a brilliant performance against Manchester City on debut, before backing that showing up by putting in a commanding display against Liverpool at the weekend.
And Allardyce said: “He looks great, doesn’t he? The good thing for me is he was so happy to be here.
“When you get players coming to a club in the position we are in the Premier League with a big smile on their face it can hopefully have an effect on the other lads.”
Kone was one of a number of additions that Sunderland made in the January window, and the new recruits seemed to have strengthened the North East based side.
Jan Kirchhoff and Wahbi Khazri also started against Liverpool, and the pair both showed their class at Anfield.
Despite their improvements, it seemed that Sunderland were set to fall to a defeat at Anfield, when Liverpool established a two-goal lead.
However, Allardyce’s men fought back and scored two late goals through Adam Johnson and Jermain Defoe to rescue a draw.
The point has kept Sunderland in 19th place in the Premier League table, four points away from safety.