Since the access time is faster on the Raptor, that will be faster most of the time. If you are video editing or such, the RAID array will be faster. I was going to get 2 200 GB WD's in RAID 0, but I got a good deal on Raptors, and decided to go with 2 74GB Raptors in RAID 0. In that case, you get fast access times and fast read/write speeds due to the array. A RAID 0 array will always beat a single drive Raptor ( well unless you are using 8.4 GB drives, lol.) It depends what the drives will be used for. I use my system for video editing, so the Raptors really help. According to HD Tach, the Raptor tag team gets 112 MB read, and about 80 MB read.
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