Animation plays too fast when when reopened

[Anonymous]

My animation FPS is set both then and now at 24FPS on preferenes window. 

When I was working on graph editor for the first time it did play as 24 FPS. 

When I closed & reopened my .mb file, the animation is going much more faster. Looks like somewhere under 10 FPS.

I had to increase my FPS in the FPS tab at the bottom right corner, to 80 to get back to where it was before.

I did not edit any preferences, why is this happening? 

[hamsterHamster]

10 FPS would be... SLOWER

Playback speed could be slowed down because of scene complexity.. even you re-open the file which was just playing at 24fps, the computer's mem can be full. This can happen when your Playback mode is set to Every Frame.  If this is the case, try decreasing calculational complexity in the viewport: e.g. turn off smooth poly display, enable Prefs>Settings>Animation>EvaluationMode:Parallel.