Choosing storage devices

HDDs. Features and use

HDD stands for «‎hard disk drive» and is more commonly known as a hard drive. Just five years ago, HDDs were being installed as a data storage device in almost all laptops and PCs. Today, 99% of laptops on the market don’t have HDDs (only SSDs, which will be discussed later).

A hard disk drive is similar to a turntable and has a similar operating principle to a tape recorder. There are several magnetised aluminium plates inside the case. During recording and reading they rotate at around 250 rotations/sec making a characteristic noise. The reading head is a few nanometres away from the platters. A single HDD can hold several TB of data, but write and read speeds are slow. Therefore, hard disk drives are recommended for systems that will read and write infrequently: as home storage, backup media or as a surveillance server.

SSDs

Solid-state disk is a non-mechanical memory device based on a set of microchips compactly placed on a single board and a controller. The principle of operation is similar to that of an ordinary flash drive. Solid-state drives are mostly used today as storage devices in compact gadgets such as smartphones, netbooks, tablets and notebooks.

SSDs are slowly but surely replacing HDDs with a number of advantages.

Advantages and disadvantages

One major disadvantage of HDDs is that they contain rotating parts, which results in noise and heat during operation. SSDs have no moving parts and therefore do not have this disadvantage. The exception is PCIe SSDs, which can become very hot, so a heatsink is included with the M2 SSD on modern mid- and premium segment motherboards. The SSD is also smaller and significantly lighter. SSDs have a limited number of write cycles but read and write operations are much faster than HDDs. HDDs use more power and are more susceptible to electromagnetic fields.

HDDs need to be defragmented regularly to maintain performance. SSDs, unlike HDDs, resist thermal shock and vibration, but if damage occurs, data can hardly be recovered.

A compromise solution is found in hybrid storage solutions. They combine the strengths of HDDs and SSDs: high capacity at high performance at an affordable price.

A comparison in numbers

SSD is 15x faster than HDD to boot up your system.

Peak-load consumption:
HDD — up to 7W;
SSD — up to 2W.
Conclusion: moving to an SSD will reduce the power consumption of the storage subsystem by 80%.

The maximum capacity of a modern SSD is 8 TB, a HDD is 20 TB.

HDDs have a maximum read speed of up to 90 Mb/s and an access time 13 ms.
SSDs have an average speed of 600 Mb/s and an access time of 0,2 ms.

A little about interfaces

It is not only the technology used to build a storage device which is important, but also which interface it uses.

An interface is a device that converts a signal and transmits it from one system component to another (in this case, from the drive to the server).

The most common interfaces used today are SATA (Serial Advanced Technology Attachment) and SAS (Serial Attached SCSI). SATA lags behind SAS in performance, but it is more affordable. It is commonly said that SAS is only appropriate for heavy systems that handle a high number of simultaneous requests. SATA is more widely deployed and suitable for larger, but lightly loaded systems.

HDDs can be connected via both of these interfaces while SATA and other types of interfaces are used for SSDs.

All modern motherboards include an M2 socket to accommodate SSDs of the appropriate format. These SSDs can run either through the familiar SATA interface or through the faster PCIe interface, depending on the motherboard and the SSD itself.

Another factor influencing your decision to choose an SSD is the form factor, which is the shape and size of the SSD:

• the classic 2.5-inch SSDs, which are similar in shape to traditional HDDs and suitable for most laptops or desktops, operate via SATA;
• M.2 with a tiny form factor is the standard storage type for thin PCs and notebooks, supporting both SATA and PCIe interfaces;
• mSATA (miniSATA) drive is a smaller version of a full-sized SATA SSD and supports only the SATA interface;
• U2 drives, which look like a 2.5-inch drive but are slightly thicker, send data over the PCIe interface.

Should you switch to SSDs

For data storage applications where fast data throughput is not a priority (e.g. data warehouses, backup systems, video encoding, data management, and large, lightweight servers) an HDD is recommended.

If you prioritise the speed of your home computer or laptop, switching to an SSD can make all the difference. The computer will load the OS and execute commands quickly, consume less power, and run cooler. An SSD also requires a lot less case space (you can put together a tiny system unit with one). Apart from computers, SSDs would be the best solution in a high-load system and CMS. In today's reality, an SSD is a good choice as the primary drive for the system, but when choosing a second drive pay attention to the required capacity. For really large volumes (over 2TB), it makes sense to purchase a HDD, as in this case the price difference will be significant.

CMS is a content management system. Its main purpose is to facilitate the collaborative process of content creation and editing. It is used in enterprises and for the handling of web content.

If you are not ready for big expenses, but need storage, we will be glad to help you with advice (contacts) on the choice of storage and we will provide our own cloud storage for your needs.