If it is just a chip on the MB then it is most likely FAKE RAID. FAKE RAID does not incorporate a full RAID model and relies on the OS to actually do most of the work. The problem is that these chips are propritary and the interface is ill defined and not truly standard
Now just for your information RAID 0 is the most dangerous RAID type. Yes it is fast but what it does is write every other sector to a different drive. If you lose either drive for any reason you have lost your data. There is almost zero chance to recover.