i5-3570k @ 4.2 not good enough for Demon's Souls?

I tried Demon's Souls recently and it performed horribly on my system. Rolling or attacking caused framedrops, the game would hang for several seconds constantly and even in the opening FMV the frames were all over the place. The settings were default aside from setting the graphics to Vulkan and Write Color Buffer to ON.

Is this processor not gonna cut it or was I missing a certain magical setting? I didn't mess around with the SPU threads so I'm wondering if those magically fix the FPS.

I played DS in this same CPU about 1 year ago and it was  a pain that time. Some areas (world 2-1 and 3-1 for example) get big FPS drops and terrible audio stuttering, but I suppose today versions improved. Maybe you should try different emulator versions, because some updates sometimes worsen performance.