Thing about raid 0 is the chance of losing all your data, if one drives goes, you lose all your data, this is why here at tech forums we generally recommend you either backup alot or get raid 0+1 which has more disk mirroring the raid 0 and is therefore more expensive. Generally as long s you backup often you will be fine but you better of going with a 640gb black as there isn't really that much differnce and you will see alto more gain from a ssd like hikari said.