Which is more performance intensive, animations or tweening?

As I said in the title, which would be more damaging to performance on a big scale. For example if I wanted to have a bunch of fans constantly rotating in my game if I was using TweenService or animations to move them which would start slowing down performance sooner the more fans I added?

I feel like animation would work much better on a larger scale compared to TweenService since I used TweenService to animate a bunch of stuff moving along a conveyor belt at all times which caused a pretty big dip in performance. I wanted to see if anyone had any experience with this and had some advice

Animations are the most efficient. Tweens have to do some sort of calculating while animations are kinda already “written” in advance