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The PC Storage Guide for the Masses

  1. Introduction
  2. Internal Drives Connectivity Options
  3. External Drives Connectivity Options
  4. Storage Method: Mechanical Drives
  5. Storage Method: Solid-State Drives
  6. Stuff to check before purchasing storage
  7. View All

This is the most long-running storage type of PCs and devices like notebooks. Hard drives have series of storage platters within a tightly packed casing. This is done to protect the platters as they are magnetically sensitive. You could relate these storage platters like a CD or a DVD. However, there are many types of mechanical components within the hard drive.

Before we into the specifics, we need to understand that there are types of two types of HDD form factors- 3.5″ and 2.5″.

3.5″ drives are made for desktop PCs, and 2.5″ are usually made for notebooks, mini-PCs, small form-factor PCs, Intel NUCs, etc. but can also be used even with DIY PCs. Both use standard SATA type connectors for power and data. However, all case manufacturers provide cases with an option to mount both 3.5″ and 2.5″ drives for some time. Usually, the 2.5″ mounts are provided typically for SATA-based SSDs (Solid State Drives) as that’s the only form factor they are used in, but there’s no restriction to prevent using 2.5″ mechanical drive, should you choose to do so. That being said, due to the dimensional difference between a 2.5″ and 3.5″, power consumption, storage space, etc will have certain differences.

When the system turns, the platters within the drive turns around at a particular speed. These are referred to as rotational speeds Companies like WD and Seagate have variable rotational speed which varies depending on the load and the requirement to get data from the drive. This also helps to provide minimum power consumption when idle or putting system on sleep mode, but also it takes time to spin up the drive for the system to access the data from idle/ low spin mode or to wake up. The low-cost drives usually spins at 5400 RPM. The mainstream ones typically run at 7200 RPM and the higher end ones are usually at least 10,000 RPM.

Because of multiple moving components within a drive, a system would take certain amount of time to do a certain task- from booting a system, to running a software or games, running movies and a lot more. This is called areal density. The more the areal density of the platter on the drive, the more data it allows you to put per platter.

Typically, in a 3.5″ drive you find up to platters that manufacturers can put in, but a lot of research and development is done in all aspects. Because of the 2.5″ form factor that typically for notebooks, network and even mini PCs, the amount of platters can be seller. There are size variants (thickness/Z Axis) in 2.5″ form factor, starting from 5mm for slimmer devices like ultrabooks and even slim form factor external storage drives, 7mm for standard size notebooks, mini PCs and much more, to a former standard 12.5mm but with the ability to provide more platter counts and also more space, followed by 15mm for Enterprise/industry specific use.

The benefit (for now) is that depending on the capacity of the drive you chose, hard drives can storage a lot more data per platter in comparison to NAND based storage per chip/per side of the PCB with a reasonable cost.

They are as follows:

  • Consumer Hard Drives

These are standard drives for internal desktop use. Nothing out of the ordinary, but they have multiple variants and series which are differentiated from each other based on HDD platter’s internal rotational speed, Cache Size and storage capacity.

  • Notebook drives


These are in 2.5″ form factors only, with a variable thickness which is referred to as the Z-axis. It was originally made for notebooks which eventually was used in prebuilt HTPCs and mini PCs. These are typically between 5200 RPM, 5400 RPM and 7200 RPM as of now. If you plan on upgrading your system with a new 2.5″ drive, typically they would cost more compared to 3.5″ drive depending on the total capacity and performance series they fall under.

  • Enterprise HDDs

These are made for industry-specific uses and cost a lot more than standard hard drives because of added functionalities. These are made for 24/7 usage environment where multiple users access, read and write data. They’re usually used for hosting websites, databases and even in a medium-to-large database networks. These typically run at 10,000 RPM to up to 15,000 RPM. Enterprise drive use Serial Attached SCSI (SAS) and even fiber channel, which provides much higher transfer rate than the typical SATA form factor.

  • NAS HDDs

For a home and office use, hard drive makers have made units which have best of both worlds- consumer with few functions typically found in Enterprise drive, but fine-tuned for NAS. They are usually designed with certain power options that are used in Network-attach storage, and even certain functions that reduce vibration typically needed for more than single-drive based NAS units. Units are known to operate even at low temperatures and higher reliability required for 24×7 usage. Depending on the brands, there are proprietary features that provides a lot of functions including expansion compatibility with a variety of NAS units of any brands.

While these are more expensive than standard consumer drives, they have a good use. These also carry a much longer warranty period (5-years as of now) and even telephone support depending on the country you’re living in.

  • Surveillance Drives


As self-explanatory they made sound, Surveillance HDDs are made specifically for Digital Video Recorder (DVR) and Network Video Recorder (NVR) that’s used to record images and video from a series of surveillance cameras.These are made to be used for 24×7 environment, but the different is that it’s specific to this usage. They are made to reduce any errors of pixelation and even interruptions that would happen at the time of recording them from the cameras and CCTVs in real-time. They are also made to ensure that all this is done with up to a certain amount of CCTVs (usually up to 32 cameras), always-on high definition recording, provided the CCTVs supports that resolution. These are made primarily to be write-intensive and also for streaming. Though these are made for low-power consumption, due to the form factor most surveillance purpose recording units have, they can become hot pretty easily, but these are recommended for high-temperature environments too. These are also made to withstand variable temperatures and vibration in surveillance equipments that are usually much smaller and cramped units. These are also made sure to provide hassle-free compatibility with multiple types of chassis for surveillance purposes and also with chipsets made for surveillance recorders.

  • Hybrid Drives

Hybrid drives are known to provide the ‘best of both worlds’ and usually made by mechanical storage makers. There are two variants of Hybrid drives- one which uses a small NAND on a mechanical drive for a much better read/write cache. While this might not be as quick as SSD variants, it provides a better loading time compared to a typical mechanical drive. Seagate Momentus XT series is one good example and found in both 2.5″ and 3.5″ variants.

The second variant has a PCB with enough NAND storage and a dedicated controller good enough for a primary drive to install your operating system and some of your programs on. The second part within the unit is a mechanical drive. Once the operating system is installed and booted to the main screen, the user needs to use a provided software to format the mechanical component of the unit. Once it’s done and formatted, the user can use the mechanical drive for mass storage. Though this can be used even in desktop systems, this is considered as a good option for notebook and ultrabook users that have a single drive cage. This way, a user can have a good enough SSD space for an operating system and certain applications while having an internal mechanical storage for keeping data. WD Black² is a good example of such drives.

  • External Drives

Many manufacturers have different models, sizes, capacity and connectivity to provide portable storage. Just like internal drives, the external drives have HDDs either with 2.5″ or 3.5″ form factor. Such units usually have a sealed unit which voids the warranty of the drive should the casing be removed or damaged. Usually, these drives have a direct USB 3.0 or any other  external interface and not SATA-based. There is a threaded mount along with the screw on the motherboard between these standard lengths so that a user can secure the M.2 drives properly.

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