Farrell is aiming to sign off before starting his Lions role with another win after Ireland bounced back from their All Blacks defeat with victories over Argentina and Fiji.
Australia, in contrast, arrive in Dublin on the back of a disappointing 27-13 loss to Scotland at Murrayfield on Sunday.
Under Schmidt, who replaced Eddie Jones in January, they had already beaten England and Wales in this autumn campaign after a miserable Rugby Championship in which they lost five out of six matches.
“I think it’s progressing exactly how we thought it would do,” Farrell said when asked about Schmidt’s impact on the Wallabies.
“He’s taken his team by playing a good few players first and foremost and took a little bit of pain but he’s done the right thing for the squad, so he’s got a good opinion and they’re reaping their reward for that at this moment in time.
“They’ve always got the athletes. He’s trying to find out about them more personally I would have thought over the last six months. He’s got that now and he’s got them playing really good rugby.”