Table of Contents
The interesting result is that the CPU speed of the system plays virtually no factor in the speed of the drive. Pentium 4 systems and dual Xeon systems all score in the 5,600 range for overall hard drive benchmarks. It is important to note, however, that a few of our benchmarks using the A8N-SLI motherboard scored in the 6,300 range! This significant increase was due to the fact that the 74GB Raptor drive supports native command queuing, which is used on the A8N-SLI motherboard. Newer controllers and motherboards should also be using this NCQ technology, so if your SATA hard drive supports it, you’ll benefit from this increase.
Native Command Queuing
|Traditionally hard disks on the consumer desktop side process disk requests in a linear fashion. This can potentially be a very bad thing and to understand why, there has to be a basic understanding of the physical structure of a hard disk. Hard disks are made up of platters or disks, much like a compact disk. Each platter is divided into tracks which are concentric circles, tracks are divided into sectors. Each platter is read by one or more heads. Seeking data is fastest when the data resides on the same track. Moving between tracks is time consuming. Consider the case where there are three pieces of data, one on the outermost track, one on the inner most track and one on the outmost track. In a traditional hard disk, the data on the outer track would be read first, then the data on in the inner track second, and finally the third piece of data on the outer track is read. This is not efficient and the time it takes to move the head is the seek time. If the head movement can be minimized, the seek time will decrease accordingly. This is where NCQ comes in – NCQ can rearrange the order of instructions so instead of moving from the outer track to the inner track, both pieces of data may be read from the outer track first before tackling the inner track.|
So, we see that while the speed of the computer plays very little role in the performance of the disk, NCQ does make a difference.
Frankly, I was surprised by the results! They show that SATA has a performance advantage! 10K RPM Raptor SATA drives appear to be on par with the performance of even a 15K RPM SCSI drive, and with NCQ, SATA even holds a very significant lead!