I've read that placing them in RAID-0 will not give them only one SATA-II channel, but two. So you should have about 6Gbps on the interface. (I'm not sure about this!)
But even 6Gbps can be a bottleneck in sequantial writes, it seems, since that setup peaks at more than 900MB/s.
So I guess: Yes.
(Btw, I'd probably recommend Samsung 830 series instead)