No, the PAL version uses to be slower 'cause it only runs with 50 FPS. The NTSC versions (U/C and J) run with 60 FPS, which are 10 FPS more than PAL.
But that only applies if the PAL version got no 60 Hz mode. Some games - like Resident Evil Remake / Zero / 4 - got an optional 60 Hz mode in PAL territories which allows them to run at the same speed as their NTSC counterparts if the user's (PAL) tv set supports it. There are even titles that require a 60 Hz supported tv or they won't run (Geist, for exmaple, is such a game). In the end it doesn't really matter 'cause it all depends on how Dolphin handles a particular version of a particular game...
But that only applies if the PAL version got no 60 Hz mode. Some games - like Resident Evil Remake / Zero / 4 - got an optional 60 Hz mode in PAL territories which allows them to run at the same speed as their NTSC counterparts if the user's (PAL) tv set supports it. There are even titles that require a 60 Hz supported tv or they won't run (Geist, for exmaple, is such a game). In the end it doesn't really matter 'cause it all depends on how Dolphin handles a particular version of a particular game...