NASA's press conference said the result was in the upper end of the predicted range, which was between "a few minutes and several tens of minutes" depending on the (unknown) physical makeup of Dimorphos.

Studying the impact and debris plumes is expected to help scientists learn more about Dimorphos.

I linked the press conference as primary source in my sibling comment if you're curious, although it didn't go into much more detail: https://news.ycombinator.com/item?id=33169879