https://wccftech.com/galaxy-s9-new-cooling-solution/

As efficient as the Exynos 9810 or Snapdragon 845 is going to be inside the upcoming Galaxy S9 it will still need an effective amount of cooling. Failure to implement such a cooling solution will mean that the flagship will not be able to perform at its optimum level and readers might not get impressed with future leaked benchmarks.

A new rumor suggests that Samsung is working on an advanced cooling solution so that the Galaxy S9 will not be forced to have its processor running at slower speeds just to keep the temperatures low.