What Is a Fixed Disk, and Why Is It Important?

Hard disk drive

What Is a Fixed Disk, and Why Is It Important?

Key Points

  • A fixed disk refers to a storage medium on a computer that is permanently installed, such as the primary storage or hard drive.
  • Mechanical hard drives and solid state drives are two types of fixed disks commonly used in computing.
  • Fixed disks are used for storage, backups, and RAID arrays in modern computing.
  • Fixed disks are crucial to modern computing as they provide stable and affordable storage solutions.

Have you ever been curious about the term “fixed disk” in computing? A lot of terminology and jargon surrounding computers has its origins in the earliest days of the medium itself. Fixed disk is no exception, with the term being tossed around as far back as the 1950s. However, this does little to explain what it is and how it works. Thankfully, modern technology has kept the fixed disk relevant, but it goes under some decidedly different names now.

What Is a Fixed Disk Really?

A fixed disk refers to a storage medium on a computer that is permanently installed. This differs from other disc drives, like floppy or CD-ROM, due to the storage medium not being a permanent fixture in the operation of the computer. More commonly, you could refer to a fixed disk as the primary storage of a computer or its hard drive.

Now, hard drives come in all different shapes and forms these days but were decidedly rarer in the world of computing 50 to 60 years ago. While the nomenclature has largely evolved past the need for calling a hard drive a fixed disk, it is still a persistent term.

The original thought was that a hard drive would be installed in a permanent enclosure, like a modern hard drive and SSD cages. You couldn’t readily remove the disk to swap out your storage; it was a more involved process. That said, it is a term that has stuck for decades despite removable storage no longer being quite so prevalent.

Different Types of Fixed Disks

Fixed Disk
Mechanical hard drives are what the term fixed disk originally described.

Permanent storage mediums are nothing new in the world of computing. You’ve likely heard some of these constantly over the last few years, with a few notable standouts that will be covered. What constitutes a fixed disk has also changed as computing has evolved.

Mechanical Hard Drives

Mechanical hard drives are arguably the oldest fixed disks in constant use. They store data on a ferromagnetic disk that revolves on a platter. Mechanical disks are more prone to shock and damage but are longer lived than their solid-state counterparts.

Chances are that if you’re looking for vast storage, a mechanical hard drive is the storage medium of choice. While they don’t have the best throughput and read/write speeds, they are cost-effective and reliable. Mechanical hard drives have fallen out of favor for primary operating system drives, but still see use in server storage, RAID arrays, and network access storage.

Solid State Drives

Solid state drives are similar in concept to RAM, using volatile flash memory to serve as a primary means of storage. SSDs have the benefit of speed, with much faster throughput and read/write speeds than their mechanical counterparts.

This does have some drawbacks, unfortunately. You’ll typically find most SSDs have a shelf life rated in a matter of years. The chips that comprise the primary storage eventually lose their efficacy, and you’ve got a dead drive.

That said, costs have come down considerably, and you really should be updating drives every few years. SSDs make for a great storage medium for vital applications, games, and your operating system. They’re further divided into a few different form factors like standard SATA drives, NVMe, and M.2 among others.

Different Interfaces Used

fixed disk
SATA connections are one of the most common modern interfaces used on mechanical hard drives.

Arguably the most noticeable difference you’ll find in computing is how much the interfaces used by storage have evolved with the times. One of the more common connections for hard drives was SCSI, or the Small Computer System Interface. This was a universal serial bus and could be used for hard drives, tape drives, CD-ROM, floppies, and a whole host of other peripherals.

SCSI has terrible throughput, at least by modern standards. SATA, or Serial Advanced Technology Attachment, is still in wide use with mechanical hard drives and solid-state drives alike. Chances are that if you’re buying a pre-built desktop or laptop, it might still be using SATA as its primary interface.

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SSDs have the benefit of using M.2 slots and PCI-E lanes for additional speed. These are more expensive drives, but they aren’t held back by the maximum bandwidth of the SATA standard. Oddly, USB external hard drives and SSDs are also considered fixed disks. In a way, it is less about the intent these days, and more about the storage medium itself.

What Makes a Fixed Disk?

A fixed disk can be thought of as a larger, more permanent storage medium for all of your computing needs. In the early days of computing, punch cards, floppy disks, and tape weren’t uncommon. However, these storage mediums weren’t something permanently installed into a computer.

While hard drives and SSDs have the option of being external devices with extreme portability, the fact remains that these are fixed volumes. You won’t be removing the actual storage device to swap it out with another as needed; you’d be deleting files or formatting the drive itself to accomplish the same goal.

Modern Examples and Use

So, what are fixed disks actually used for these days? Well, as you can imagine, they serve as a vital component for computers big and small. Every device you touch or handle on a daily basis likely has a fixed disk which acts as the primary storage medium. While the names differ, the overall intent is the same. That said, let’s take a closer look at some of the use cases for fixed disks in 2023.


Storage is arguably the primary use of fixed disks in the modern era. Everything in computing takes space; it exists as data with hard values and storage needs. As such, you need a minimum volume of storage to actually handle your daily operations with a computer.

That isn’t even getting into all the other things you can do with a computer, like gaming, graphic design, and so forth. The point is that you’ll need storage, and a fixed disk provides that in ample supply. You aren’t beholden to the 1.44-megabyte limits of a floppy disk for applications and data storage these days.


Now, those in the know about IT are aware that magnetic tape is still the most stable form of long-term backup. However, not everyone has the drive or need to embark on the journey of digital tape. For everyone else, a fixed disk makes a great option for regular backups.

You can spread data to multiple drives because redundancy is always a good thing. If you’re working in a data-heavy field, it is an absolute must to have some form of data to maintain business continuity.

Fixed disks excel as backup solutions; they’re low-cost, easy to maintain, and relatively simple to replace. Now, you could debate the particulars of which drive type is best for long-term solutions, but the fact remains that much of modern computing uses fixed disks for backups.

RAID Arrays

fixed disk
RAID configurations use multiple fixed disks to provide redundancy or data continuity.

A redundant array of independent disks, or RAID, is a way of maintaining continuity and safety with your drives. Fixed disks can be wonderfully stable, but the old saying goes that two is one and one is none. If you’re running a server or some other mission-critical piece of equipment, a RAID is a great way to maintain parity with all of your data.

It falls under the same general umbrella as storage, but this is intended for larger and more important storage volumes. RAID arrays are used with the likes of servers, as previously mentioned, and network access storage. There are a few different RAID types, and it really depends on your needs for one. However, it allows you to retain data continuity in the event of a drive failure.

How Important Are Fixed Disks to Modern Computing?

Fixed disks are a crucial component of modern computing. Yes, removable storage mediums still exist, but nothing really beats the portability of an external SSD. That said, your average computer user isn’t likely to keep stacks of CDs, cases of floppies, or racks of tapes around these days. A fixed disk is the way to go, and larger, more stable volumes of storage are more affordable than ever.

Frequently Asked Questions

Are fixed disks still in use?

Absolutely, you likely have one as the primary storage device in your laptop or desktop right now.

Have fixed disks always been part of computing?

No, but they have been part of computing for decades now. Prior to their introduction, data was stored on punch cards. As such, you can see why they are so crucial for any sort of serious data storage. An errant tear could render a punch card useless, but fixed disks are far more robust.

Do mobile phones use fixed disks?

The terminology is different surrounding the storage on a smartphone or tablet. However, the intent behind their storage is largely the same.

Is data really stored on tapes?

Absolutely, data has been stored on reel-to-reel tape, VHS, and cassettes. Tape is stable when kept out of humid environments and has an effective shelf-life of decades provided the ferromagnetic coating is high quality.

Are fixed disks an important development in computing?

Yes, you could easily argue that having permanent and stable storage has helped advance computing as a whole.

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