No, RAID-1 isn't designed to stripe data. The only way to make this possible would be to set a "stripe size" (in quotes since it isn't being striped) that matched the block size that the volume is formatted with, and that is variable based on which filesystem you are using, so there wouldn't be an easy way for the card to make this assumption.
Theoretically RAID-1 can gain STR when reading because the same data is on two drives and it can read half of the data from each drive. However, very few RAID cards do this, but it is definitely possible and has been implemented by some RAID cards. Seeing that the Perc cards are fairly high end cards, I thought they might do this.