One of the Raptor 150's major new features is the ability to support NCQ (Native Command Queuing) technology. NCQ, when active, allows the drive to re-order read/write commands to process them quicker, instead of processing commands in the order in which the drive received them. In theory, this should mean NCQ is faster in just about every scenario, especially during heavy multi-tasking where you're reading data off of different sectors of the hard drive. NCQ, heralded as the "next big thing" for hard drives, is suffering from a backlash of sorts recently. Many users are claiming that you can receive better performance by turning NCQ off.
Sure enough, while running our disk benchmarks, we were confounded that the new Raptor 150 drives were not performing quite as well as expected. Luckily, the Areca 1220 PCIe RAID card we tested with allows you to enable and disable NCQ technology through its software interface, and doing so improved our benchmarks by quite a lot in some cases. Now, we had expected that disabling NCQ would help in some of our benchmark scenarios, but amazingly, nearly all of our benchmarks showed performance improvement with NCQ disabled. Here's a quick breakdown of the performance differences we saw with a four-disk RAID-0 array of Raptor 150 disks with NCQ enabled and disabled.