FPS drop at certain point

[Shichiya San]

As stated,I've enjoying Super Paper Mario for a while
But for whatever reason,every time mario specifically travelling down the pipe/going through the door/switching dimension ,the emulator automatically scale it to 30fps,which slows down the game
After finish travelling,the fps is normal again
OR
When the emulator game window is not focused,the fps immediately bounce back to 60 fps.
Is there any reason why this is happening,or what cause it to be like this?
Although it's still playable,it annots me a little.would gladly take any suggestion.
   

[JosJuice]

Maybe it only is lagging a little but vsync forces it down to 30 fps? Try turning off vsync.

[JMC47]

Your processor is a bit old and Bounding Box is incredibly demanding. It's probably slowing down due to bounding box effects used for the pipe animation. You can try lowering the internal resolution or changing backends, as each backend has its own way of doing bounding box.

[Shichiya San]

(09-30-2018, 02:27 AM)JMC47 Wrote: Your processor is a bit old and Bounding Box is incredibly demanding.  It's probably slowing down due to bounding box effects used for the pipe animation.  You can try lowering the internal resolution or changing backends, as each backend has its own way of doing bounding box.

I doubt my processor is not enough to run this game,since I'm able to run most 3A games at around 60fps. However,I'll try lowering internal resolution to see if this change.
p.s. my CPU usage is always below 60% when playing

[JosJuice]

(09-30-2018, 03:06 AM)Shichiya San Wrote: I doubt my processor is not enough to run this game,since I'm able to run most 3A games at around 60fps.

Dolphin's CPU needs are rather different compared to the CPU needs of normal PC games, especially when using especially demanding features like bounding box.

(09-30-2018, 03:06 AM)Shichiya San Wrote: p.s. my CPU usage is always below 60% when playing

Dolphin is only able to use one or two cores fully, so Dolphin will never be able to use anywhere close to 100% CPU if you have four cores or more.

[Shichiya San]

Huh,so it's the v-sync which caused the problems.
But hmm,a simple teleporting animation shouldn't slow down the game,I wonder why
Anyway still gonna use V-sync tho,screen tearing is unbearable

Thanks for the support!

[JMC47]

The game uses an incredibly hard to emulate effect for those transitions. It makes 100% sense why it lags on your processor during transitions.

[Shadorino]

You're rocking a 9-year-old i5 CPU, it's not surprising that it has difficulty handling Bounding Box. And then there's also V-Sync.
Consider upgrading you CPU/Motherboard/RAM combo early next year, when the new Intel CPUs are out and the RAM prices not BS anymore.