Demul slowed down and doesn't get to 100% speed anymore

[gungunner]

Hi
I was using the latest version of demul which worked at full speed for both dreamcast and naomi games.
I tried the video options to stretch the image and render at 2x and demul started running slow. I reverted to the previous settings and it still runs slow.
I extracted demul at a different folder to get a fresh config and I get the same results (30 to 40 fps)
I even tried with an older version of the emulator and it's the same

What could be causing this and how could I fix it?
thanks for your answers

 

[the_grable]

I've had a similar issue. I use Demul to play hokuto no ken on the atomiswave emulator, and it used to run just fine. Now it runs really slow and the sound is warped as all hell.
I was able to partially fix it by turning on vsync, but sometimes it still has audio errors and short slowdowns.