Disabling it causes the emulator to run in interpreter mode, very slow, you should never need to disable that option.
dynarec is the recompiler converts psp instructions to pc instructions on the fly, usually very efficiently it might recognize a sequence of instructions and rewrite them more efficiently for the pc to understand ..etc
Where interpreter has no shortcuts it's probably more accurate but will be slow.
You can take a look at compiler.xml to get a better idea what dynarec does.
dynarec is the recompiler converts psp instructions to pc instructions on the fly, usually very efficiently it might recognize a sequence of instructions and rewrite them more efficiently for the pc to understand ..etc
Where interpreter has no shortcuts it's probably more accurate but will be slow.
You can take a look at compiler.xml to get a better idea what dynarec does.
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