Quick Answers
The hard drive is most commonly located inside the computer case, attached to the motherboard. However, with the growth of external and portable hard drives, the hard drive can also be located outside of the computer case. The traditional location inside the computer provides protection, connectivity, and space to mount a 3.5″ desktop hard drive. But the increasing need for storage capacity, backups, sharing files between computers, and portability means that external hard drives are also very common.
Inside the Computer Case
For desktop computers, full sized towers, and many laptops, the hard drive is traditionally mounted inside the computer case. There are a few reasons why this is the normal location:
Connectivity to Motherboard
The hard drive connects directly to the motherboard via SATA cables. This allows for fast transfer speeds to access files, boot the operating system, and run programs. If the hard drive was located outside the computer case, it would need to connect via slower external cables like USB or eSATA.
Space for 3.5″ Drives
Most desktop hard drives are 3.5″ width drives, which will not fit well externally. Laptop hard drives are 2.5″ drives, but are often still placed inside the laptop case rather than externally. The large computer cases provide ample room to mount multiple 3.5″ hard drives.
Protection
Inside the computer case, the hard drive is protected from accidental drops, bumps, liquids, and other external hazards. Computer cases are designed to be protective housings for sensitive internal components. Portable external hard drives are more prone to physical damage.
Heat Management
Inside the computer case allows for better heat dissipation from the hard drive to keep it cool and prevent overheating. The external drives have less air circulation and need to rely on passive cooling.
Security
Internally mounted hard drives are also more secure against theft of the physical drive. While the data can still be accessed in other ways if the computer is compromised, the hard drive itself is kept safer inside the case.
Evolution of External Hard Drives
While internal mounting has been the traditional standard, external hard drives have become very commonplace and continue gaining popularity. There are several reasons driving this evolution:
Portability
External hard drives are small enough to easily move between locations, make backups, transport large files, or expand limited storage on laptops.
Expanding Capacity
Internal hard drives are limited by the number of bays and size in a computer case. External drives can provide almost unlimited storage expansion.
Backup
External hard drives make it easy to backup your computer files for protection against crashes or data loss.
Sharing Files
External drives allow for simple file sharing between computers, networked drives, and sending files to others.
Working with Multiple Computers
External drives give you flexibility to work on files across multiple computers with incompatible internal drives. Just plug into the USB drive between machines.
Media Libraries
Large external drives are ideal for storing photos, videos, and music libraries that can be accessed from multiple devices.
Gaming Consoles
Game consoles like Xbox, PlayStation, and Nintendo Switch rely on external hard drives for expanded storage capacity.
Smart TVs
Smart TVs with storage capacity for downloaded apps, games, movies, and shows will often have an external USB port to augment the limited internal storage.
Cloud Storage
While not physically external to the computer, cloud-based storage on servers allows for anywhere access from multiple devices. It serves a similar role as external drives.
Typical External Hard Drive Types
There are a few common physical designs and connection types for external hard drives:
Portable Hard Drives
These compact drives are small enough to fit in your pocket and powered by the USB cable. The storage capacities range from 500GB to 5TB.
Desktop External Drives
Designed to stay stationary on your desk, these drives require an AC power cord. They offer larger capacities up to 10TB or more.
Gaming Hard Drives
Engineered for the demands of high performance gaming, these portable drives connect via super fast Thunderbolt 3 cables.
Wireless Hard Drives
These portable drives can connect directly to your WiFi network and be accessed wirelessly from any device on the network. Helpful for media libraries.
USB Flash Drives
Also known as thumb drives, these tiny drives are designed to connect directly to a USB port for easy transfer of smaller files. Capacities from 8GB up to 1TB.
eSATA Drives
An alternative to USB, eSATA allows connections to a SATA interface externally for higher speeds than USB 2.0. Not as fast as USB 3.0 or USB-C though.
SSD vs HDD
Both internal and external drives can use traditional spinning hard disk drives (HDD), or new solid state drives (SSD) which have no moving parts and faster speeds. SSD is taking over.
Choosing Internal vs External Hard Drives
With flexibility on both sides, is an internal or external drive better for your needs? Things to consider:
| Factors | Internal Hard Drive | External Hard Drive |
|---|---|---|
| Cost | Internal drives are generally cheaper at smaller capacities | External drives come at a premium cost |
| Capacity | Up to 10TB for 3.5″ drives, but limited by computer case | Currently up to 16TB with expanding future capacity |
| Speed | Fast transfer speeds with SATA III interface | USB 3.0 speeds can bottle neck higher speed drives |
| Portability | Not portable since it stays inside the computer | Small and portable to transport terabytes of data |
| Convenience | Easy to access files as primary drive | Requires plugging in the drive to access files |
| Security | More secure inside computer case | Small size makes external drives easy to lose or steal |
| Failure Risk | If the computer dies, the drive likely dies too | Files stay intact if computer crashes |
| Backup | Manual backups required | Makes routine backups much simpler |
| Customization | Can customize with higher performance parts | Limited changes can be made to enclosure |
The Future of Hard Drives
Some possible developments that could change hard drives in the future:
Higher Capacities
As technology improves, the maximum capacities of hard drives is expected to continue growing beyond the current 16TB barriers for both internal and external drives.
Smaller Physical Size
Continued innovations allow hard drives to shrink in physical size while maintaining or improving on storage size. Smaller external drives and micro interal drives in laptops.
Faster Interfaces
New connection interfaces like Thunderbolt 3 push speed boundaries, while WiFi and wireless external drives also open new possibilities.
Hybrid Drives
SSDs and HDDs each have pros and cons. Hybrid drives emerge combining the best of both technologies in the same drive.
Dropping Cost per TB
As manufacturing technology gets cheaper, the cost per terabyte of storage will likely decrease making tremendous capacities more affordable.
Cloud Storage Integration
More seamless integration between local and cloud storage with automatic syncing when connections allow.
New Technologies
Potentially, new technologies like quantum computing or DNA digital data storage could revolutionize computer data storage long term.
Conclusion
In summary, the default location for hard drives is internally mounted inside computer cases to provide greater connectivity speeds, protection, cooling, and security. But external hard drives are extremely popular due to the flexibility, portability, capacity expansion, and ease of backups they provide. Storage technology continues advancing rapidly, so we can expect higher performance and new innovations in the years ahead whether inside or outside the computer case. Choosing internal vs external drive will depend on your budget, performance needs, workflow, and how you want to access the data.