Some things to know when buying a computer hard disk

When buying a computer, in addition to selecting the processor (CPU), motherboard, memory (RAM), etc., we have to care about the hard drive, an equally important device, to contribute A huge part of the system's speed and stability.

Here are some issues to keep in mind:

- Communication port: Currently, choosing SATA (Serial Advanced Technology Attachment) or SATA 2 communication is necessary. SATA buses are designed in a 'sequential' (serial) architecture, as opposed to a parallel bus. Thus, SATA has a data transfer rate of 150MB / sec, much higher than the Advanced Technology Attachment. Standard SATA2 has data transfer rate of up to 300MB / sec. Both SATA and SATA2 standards can be removed / hot-plugged (when the device is running).

- Cache (cache): A temporary storage area during the hard disk's working process. Read / write does not occur immediately on the hard disk (due to the movement of the read / write head, the frequency of data transfer between the CPU and the hard disk). Therefore, incoming or outgoing data will be temporarily placed in the cache. When buying, we see which hard drive has large buffer capacity, the performance of that disk will be higher.

- Rotating speed: Currently, most desktop hard disks have a rotation speed of 7,200 rpm. A few with a speed of 5,400 rpm or 4,200 rpm are inventory or production only for use with Notebook computers (a small, compact notebook).

- Technology: If you want to optimize random access time, select the hard drive with NCQ (Native Command Queuing) technology. NCQ technology contains 32 lines of code compared to a command line for normal hard drives, which provides faster data access. If you need smoothness or noise reduction, choose NoiseGuard or SilentSeek. For computers on board, vehicles should choose ImpacGuard technology, this technology has the effect of reducing shock and vibration.

- Disk capacity: The hard disk is produced with increasing capacity, but the price is getting cheaper. However, when buying, we need to calculate how to match the demand. Do not buy discs that are too large to be unnecessary. Because if the system fails, the operating system will spend a lot of time checking the hard disk when rebooting.

The following is a list of the actual capacity of the hard disk compared to the capacity listed on the manufacturer's disc label.

Capacity recorded on disk labels

Actual capacity (writable)

40 GB

37.24 GB

80 GB

74.48 GB

120 GB

111.72 GB

160 GB

148.96 GB

180 GB

167.58 GB

200 GB

186.2 GB

250 GB

232.75 GB

320 GB

297.92 GB

400 GB

372.4 GB

500 GB

465.5 GB

640 GB

595.84 GB

See the table, we know the actual capacity of the drive to buy exactly as needed.

The above issues are for reference only and suggestions. When buying, depending on the reality and purpose of use you choose accordingly. Wish you find a hard disk with the desired performance.