What has changed in Android Studio before 2.1.2 so that Gradle starts building the project in 1.5 minutes?

Question

Android

Hello.
There is a small project in Android Studio 1.5 (until yesterday). In the end, the IDE update system persuaded me, and I let it upgrade to 2.1.2. As a result, the following happened:
1. If earlier the project was assembled in 20 seconds and launched on a live phone, now the process takes at least 1.5 minutes.
2. At the same time, the system noticeably slows down (a movie is spinning in the background) and delays are clearly audible, although earlier (before the update), everything was comfortable with this.
Computer: laptop with Win10, 8 GB RAM, Studio itself on an SSD, Core i3
As a result, I had to return to the old version, but now I have vague doubts - what did I miss?

Answer 1

Enable incremental build