Depends on the model (what capacity are the Raptors). The 600 GB versions, benchmarked in 2009, reached 130 MB/s, so they were getting close to the limit two years ago. It's an awfully close call. You may not notice any effect. Affect?
Can you put one of the Raptors on a working SATA II port and do a quick benchmark?
By the way, what is the motherboard, and do you want to try to get the other SATA II ports to work?