Two Raptors Better Than One

The Western Digital Raptor is undoubtedly one of industry's fastest Serial ATA drive. Spinning at an incredible 10,000RPM, the drive is able to handle high data throughputs via its the new Serial ATA interface which is capable of delivering speeds of up to 150MB/s. The Raptor's seek performance was amazing as it's on-par with some of the more expensive 10,000RPM SCSI drives. However, its I/O throughput is not as impressive as it's still very much limited by the SATA interface which is more than two times slower than the latest Ultra320 SCSI standard.

This really brings us to the question whether two Raptors combined in a RAID array could outperform a single SCSI hard drive. As we all know that the WD Raptor is priced very attractively below typical 10,000RPM SCSI drives, a lot of users actually asked us if they could combine two WD Raptors to give them SCSI-like performance. The motivation behind that is none other than cost as two WD Raptors are definitely cheaper than a 10,000RPM SCSI drive.

Two Raptors are always better than one.

In this article, we explore the performance of two Western Digital Raptor drives combined using the rather well-known Silicon Image SiI3112A SATA RAID controller. The results in the next few pages will give you an idea of the Raptor's RAID performance as compared to a 10,000RPM SCSI drive. We picked an older Seagate Cheetah 36ES drive for this comparison as its performance is more or less in the same ballpark. We'll also compare its results with some 15K SCSI drives.

Let's get on to the results.