NCQ - Seagate Barracuda 7200.7 ST3160827A 160G with SiliconImage Sil3124 Host Controller (1)
Bluetooth 5 Oct 2004

NCQ (Native Command Queue)

You have probably heard of this term before. So what is NCQ ? Basically in computer science, access to certain parts of system, be it disc access or even memory access can be sped up with the introduction of  a queue system.

This is so because commands can no longer need to be processed in a sequential order. Just imagine if you have a read or write request to random parts of the disc. This will definitely slow down the application as it waits for data to be read. What if there is a way to reorder commands that require access to close by sectors to be scheduled together. Wouldn't reading be faster? Yes it does.

"SATA drives that support NCQ have an internal queue in which outstanding commands can be reordered or dynamically rescheduled. NCQ also provides the critical tracking mechanism for outstanding and completed portions of the workload.. In addition, NCQ includes a mechanism that makes it possible for the host to issue additional commands while the drive is seeking data for another command." - Seagate.

With this queuing system in place, it will improve performance and reduce mechanical wear.

In our tests, we will be using the Barracuda 7200.7 160GB HDD ST3160827AS HDD paired with a NCQ enabled host controller SiliconImage's SIL3124. We will also include tests of using the same HDD with a NON-NCQ enabled host controller Sil 3112 and we will be able to see the difference in performance in both sequential and random reads/write.

Discuss in Peripheral sector

Next >>>

(C) Copyright 1998-2009 OCWorkbench.com