External hard drives provide additional storage space for computers, game consoles, media players, and other devices. As digital content like photos, videos, music, and games continues to grow in size, consumers need larger capacity drives to store and access their data. Manufacturers have responded by steadily increasing the maximum capacities of external hard drives over the years. Today’s largest consumer external hard drives can hold up to 18 terabytes (TB) of data.
What factors determine the size of an external hard drive?
There are several key factors that determine the maximum capacity of an external hard drive:
- Form factor – The physical size and shape of the drive enclosure limits the number and size of internal storage platters. Common external form factors include 2.5” portable drives and 3.5” desktop drives.
- Interface – The data transfer interface impacts max capacity. Older USB 2.0 drives capped out at 2TB. Newer interfaces like USB 3.2 Gen 2×2 support larger drives.
- Data storage technology – Higher density storage technologies like SMR (shingled magnetic recording) allow more data storage per platter.
- Number of internal platters – More platters provide more total storage surface area to write data.
- Areal density – This reflects how tightly data can be stored on a disk platter, measured in bits per square inch.
By combining the latest innovations across these areas, hard drive manufacturers can offer increasingly larger drives.
History of External Hard Drive Sizes
To understand modern large capacity external drives, it helps to look at how maximum sizes have progressed over time:
2001 – 2006: Early USB 1.1 and USB 2.0 portable hard drives maxed out at around 160GB – 500GB. The simple USB connectivity and 2.5” form limited capacities.
2007 – 2009: 3.5” desktop external drives with capacities up to 2TB emerged, enabled by more advanced data storage areal densities.
2009 – 2014: Improved connectivity standards like eSATA and USB 3.0 enabled external desktop drives up to 6TB. Portable USB 3.0 2.5” drives reached 2TB – 4TB.
2015 – present: Modern external 3.5” desktop drives can store up to 18TB. Portable 2.5” drives now reach 5TB+. Key innovations enabling huge growth:
- USB 3.2 Gen 2 for fast data rates up to 10Gbps
- Increased areal densities through new technologies like SMR
- More internal platters (up to 9+ in bigger enclosures)
Here is a table summarizing the growth of maximum external hard drive capacities over time:
| Year Range | Max External HDD Capacity | Key Factors |
|---|---|---|
| 2001 – 2006 | 160GB – 500GB | Simple USB connectivity, 2.5″ form limited capacities |
| 2007 – 2009 | 2TB | 3.5″ form enabled larger drives |
| 2009 – 2014 | 2TB – 6TB | Improved USB 3.0 and eSATA connectivity |
| 2015 – present | 18TB | USB 3.2 Gen 2, increased areal densities, more platters |
Largest Available External Hard Drive Sizes Today
Now that we’ve seen the growth trajectory for external storage, what are the biggest consumer external hard drives available on the market today?
Here are some current models that represent the largest options from major manufacturers:
Seagate Backup Plus Hub – Up to 14TB
Seagate’s desktop external drive comes in sizes from 4TB up to a massive 14TB. It has a 3.5″ form factor and uses USB 3.0 connectivity. Features include:
- Up to 240 MB/s transfer speeds
- Requires external power adapter
- Integrated USB hub for extra ports
Western Digital My Book Duo – Up to 28TB
The My Book Duo drive offers huge capacity in a RAID array configuration. It comes in versions from 4TB up to a gigantic 28TB.
- RAID-0 ready with fast transfer rates up to 360 MB/s
- RAID-1 ready for data redundancy
- Includes 256-bit AES hardware encryption
LaCie 2big Dock – Up to 28TB
Another large capacity RAID external solution, supporting RAID 0, 1, and JBOD configurations. Available drive size options range from 8TB to 28TB.
- Dual Thunderbolt 3 ports for daisy chaining
- RAID speeds up to 440 MB/s
- SD and CF card slots built in
G-Technology G-RAID – Up to 28TB
This 7200 RPM dual-drive RAID external storage system comes in capacities up to 28TB. Features include:
- RAID 0 for performance and RAID 1 for redundancy
- Thunderbolt 3 and USB-C connectivity
- Transfer rates up to 500 MB/s
For other large single drive alternatives, top models include:
- Seagate Expansion Desktop 16TB External Hard Drive
- Western Digital Easystore 18TB External USB 3.0 Hard Drive
- LaCie 2big 16TB External Hard Drive
Portable external SSDs are also growing in size, though nowhere near the capacities of desktop drives. Top models include:
- Samsung T7 Touch 2TB Portable SSD
- WD My Passport 2TB Portable External SSD
- Seagate One Touch 2TB External SSD
What is the Largest Theoretical Hard Drive Size?
Manufacturers continue to push the boundaries of possible drive sizes. But what is the absolute largest theoretical hard drive size that could exist based on today’s understanding of physics and engineering?
Current SMR and other recording technologies have the potential to reach up to around 100 terabytes (TB) per drive. But beyond this, a fundamental physical limit exists based on the superparamagnetic effect.
The superparamagnetic effect occurs when data recorded on a magnetic platter becomes thermally unstable at small sizes. This limits how densely data can be stored magnetically. Based on today’s physics, the superparamagnetic limit for hard drive storage is estimated to be around 1 exabyte per drive. That’s over 1000 TB per drive!
However, practical engineering challenges would likely prevent a single drive reaching such sizes. Factors like vibration, stability, and read/write heads would become limiting factors well before capacities could reach an exabyte. Realistically, 50 TB – 100 TB per drive is likely the practical ceiling for high capacity hard drives without major new innovations.
External SSD vs HDD Size Limits
Solid state drives (SSDs) based on flash memory chips don’t have the same physical size limitations as mechanical hard disk drives. However, SSD capacities remain much lower than HDDs due to higher costs per gigabyte of storage. The largest consumer external SSDs today are around 8TB.
Here’s a comparison between external HDDs and SSDs:
| External HDD | External SSD | |
|---|---|---|
| Price Per GB | Around $0.02 per GB | Around $0.10 per GB |
| Max Single Drive Size | Up to 18TB | Currently up to 8TB |
| Advantages | Much cheaper per GB capacity | Faster speeds, more resilience to shocks |
| Disadvantages | Slower transfer speeds | Significantly more expensive per GB |
As SSD prices continue to decline, larger capacity external SSDs will become more affordable and compete directly with HDDs. But HDDs continue to offer far greater capacities at lower price points for now.
Conclusion
In summary, the largest consumer external hard drive sizes available today range from around 14TB for single external HDDs up to 28TB for multi-drive external RAID arrays. Leading manufacturers like Seagate, Western Digital, LaCie, and G-Technology currently offer models at these huge capacities. Maximum drive sizes have increased dramatically over the years thanks to new innovations in data storage technology. While limits exist due to physics and engineering barriers, capacities are likely to continue growing over time as the need for external storage space increases. For the highest possible capacities at affordable prices, HDDs are still the best option, though SSDs are increasingly competitive up to 8TB.