The performance of moving pistons has dropped significantly in 1.14 compared to 1.13.

I've attached 2 screenshots where you can see 15 pistons being powered using an observer clock. In 1.13.2 (without optifine or other client-side mods) the FPS is a steady 60 (with is the limit I set). In 1.14.2-pre1 the FPS has dropped to 40 which is a large drop for only 15 pistons.

I've also included the world to make it easier to recreate.

I've searched the bug tracker for this issue but was unable to find it already reported.