Are portable external hard drives reliable?

Portable external hard drives provide a convenient way to store and backup large amounts of data. They can be an important part of a data protection strategy. However, like any storage device, portable hard drives can fail. So are portable external hard drives reliable?

What is a portable external hard drive?

A portable external hard drive is a storage device that can be connected to a computer, typically via USB. It provides additional storage space and allows data to be accessed from different computers. Portable hard drives are powered through the USB connection and do not require an external power source.

Portable hard drives come in a range of storage capacities, from 500GB to 5TB or more. They are small enough to be easily transported in a backpack or laptop case. Many portable drives are ruggedized and can withstand being bumped or dropped. Portable hard drives typically connect to PCs and Macs, and many are compatible with gaming consoles like the Xbox and PlayStation.

What are the potential causes of portable hard drive failure?

Like any storage device, portable external hard drives can and do fail. Some of the potential causes of portable hard drive failure include:

  • Physical damage – Portable drives are moved around frequently and can be dropped, banged, bent or crushed, leading to physical damage to drive components.
  • Overheating – Excessive heat can damage the hard drive motor and internal components.
  • Firmware and electronics failure – Corruption or failure of the hard drive firmware or on-board electronics can render the drive inoperable.
  • Motor failure – The spindle motor that spins the hard drive platters can burn out or fail.
  • Heads touching platters – Severe shock or vibration can cause the read/write heads to touch and damage the platters.
  • Corrupted file system – Problems with the file system from sudden loss of power or improper disconnection can lead to data errors and drive failure.

In summary, both physical damage and electrical components failing can result in a portable external hard drive failure.

What factors influence portable hard drive reliability?

There are a number of factors that play into how reliable a portable external hard drive will be over its lifetime:

  • Build quality – Higher quality construction typically means more reliability. Aluminum or metal enclosures protect better than plastic. Ruggedized drives can withstand more abuse.
  • Brand reputation – Major brands like Western Digital and Seagate have years of HDD experience and rigorous testing standards.
  • Drive technology – Newer drives with modern drive technologies tend to be more reliable than older generation drives.
  • Drive capacity – Higher capacity drives with more platters and heads have more components that could potentially fail.
  • Encryption – Encryption adds complexity that could impact reliability. But data is protected if a drive fails.
  • Use conditions – Temperature, handling, transportation and operation conditions all impact lifetime reliability.
  • Age – Drives generally become less reliable as they age past 2-3 years, regardless of brand or model.

What do portable hard drive manufacturers’ warranties cover?

Most portable hard drive manufacturers provide a limited warranty, typically for 2-3 years. Warranties generally cover defects in materials or workmanship that cause drive failures under normal use. However, there are limitations.

Typical exclusions from the warranty include failures due to:

  • Damage caused by improper use like dropping, fire, water exposure, electrical issues
  • Unauthorized disassembly, repair or modification of the drive
  • Data recovery services if a drive fails
  • Drives used in enterprise or industrial applications
  • Drives that have exceeded a specified number of data load/unload cycles

So while warranties provide some protection, they do not cover failures from all causes and have time limits. Purchasing an extended warranty can provide longer coverage.

What is the typical lifespan of a portable external hard drive?

There are no definitive statistics on average portable hard drive lifespan. However, a properly handled drive that is not subjected to extreme conditions can be reasonably expected to last:

  • 2-3 years for light to moderate usage
  • 4-6 years when used for occasional backups or data storage
  • 5+ years if rarely used and stored properly during non-use

Heavy users should expect portable drives to be reliable for 2 years or less. Very heavy users may see failures sooner. Higher capacity drives tend to have shorter usable lifespans on average.

What are the expected failure rates?

Industry data on portable external hard drive failure rates is limited, but general HDD failure rate research provides some guidance. Among major brands, annualized failure rates in the first 1-2 years are typically in the range of:

  • 1% – 3% for portable drives used frequently as primary storage.
  • 0.5% – 1.5% for backup drives or drives with light usage.
  • Less than 0.5% for rarely used drives in proper storage.

Failure rates predictably increase after 2-3 years, with some models seeing over 5% annual failures by years 4-5. Overall failure rate averages combine both early failures and expected wear-out failures later in life.

What are the most common causes of failure over time?

The distribution of failure causes changes over a portable hard drive’s life. Early failures are more often due to manufacturing defects. Later failures are usually due to use stresses and normal wear.

A study by Backblaze reviewed data on over 100,000 hard drives and found this split on failure causes:

Failure Cause Percentage
Manufacturing defects 27%
Random failures 18%
Physical damage 13%
Electrical damage 5%
Firmware issues 3%
Unknown causes 34%

The high rate of uncategorized failures demonstrates how challenging it is to definitively determine failure causes, even with advanced analysis.

How strictly should portable hard drive manufacturer SMART stats and hours powered on be followed?

Portable hard drives provide Self-Monitoring, Analysis and Reporting Technology (SMART) data to indicate reliability and potential for failure. Factors like reallocated sectors count, offline reallocations, and hours powered on are tracked.

These stats can give guidance on drive health, but should not be followed as strictly defined failure thresholds. Backblaze found very little correlation between SMART stats and actual drive failures. Rather than replacing drives strictly based on hours powered on or a SMART value threshold, monitor values over time and replace drives showing significantly deteriorating or accelerating SMART values.

What steps can be taken to improve portable hard drive reliability?

You can help maximize the reliability of your portable external hard drive by following usage and storage best practices:

  • Handle gently – Avoid drops, bumps, shakes and exposure to rain/liquids which can damage drives.
  • Transport safely – Use padding and secure drives when travelling to prevent internal damage.
  • Operate properly – Eject and disconnect drives properly to avoid data issues. Keep drives well ventilated and below manufacturer max temperatures.
  • Maintain drives – Periodically scan drives for errors and bad sectors. Reformat drives every couple years.
  • Control vibrations – Limit external vibrations which can damage operating drives. Place on soft surfaces.
  • Use surge protection – Protect drives with surge protectors to avoid electrical damage.
  • Store properly – Keep drives in controlled room temps and humidity when stored. Avoid temperature extremes.

Following these usage guidelines maximizes the reliability and lifetime of portable external hard drives.

How reliable are SSDs compared to portable hard drives?

Solid state drives (SSDs) with flash memory are now a viable option for portable external storage. SSDs have no moving parts and better withstand shocks, vibration, heat, and magnetism. Overall failure rates for SSDs are lower than portable hard disk drives (HDDs).

One Backblaze study found the following annualized failure rates:

  • SSDs – 1.2%
  • Portable HDDs – 2.7%

However, SSD reliability deteriorates significantly as cells wear out after substantial data writing. SSDs slow down as they near the drive’s write endurance limit. The limited write cycles and cost per gigabyte of SSDs make hard drives still preferable for high capacity frequently written data.

Should data be backed up if relying primarily on a portable hard drive?

Portable hard drives provide convenient storage and the ability to access data across different computers. However, a portable drive used as a primary data storage device is still prone to potential failure.

To protect against data loss from drive failure, undetected data corruption, accidental deletion, or device theft, it is highly recommended to maintain a second backup copy of important data stored on a portable drive.

Backup options include:

  • External drive backups – Use a second external drive and regularly copy key data to it.
  • Cloud backups – Use a cloud backup service to automatically copy important folders or entire drive contents.
  • Computer image backups – Use drive imaging software to regularly backup the entire portable drive.

Ideally, important data on portable drives should be backed up using multiple methods for enhanced redundancy. Testing backups regularly by restoring data verifies they are valid and working.

Should in-warranty failed portable hard drives be replaced with the same model?

When a portable external hard drive fails within the warranty period, you typically have the option to request a replacement drive that is the same or a similar model. However, there are pros and cons of sticking with the same model versus switching models:

Replacing with Same Model Switching to New Model
  • Maintains brand and model familiarity
  • May have same undetected design flaw
  • Life expectancy reset with new drive
  • Avoids repeat failure from flaw
  • May have greater reliability
  • Improved features and specs

For a critical high-capacity drive, switching models provides an opportunity to get a more reliable replacement. But for lower capacity drives, replacing with the same model may be adequate.

How can failed portable hard drives be recovered? Is data recovery worth the high cost?

Recovering data from a failed external hard drive is possible but often expensive. A professional data recovery service can dismantle the drive in a cleanroom and attempt extracting the data using specialized tools. This bypasses the drive’s electronics to read platters directly.

Costs for a portable external drive recovery average $300 to $1000 but can exceed $2000 for difficult cases requiring significant disassembly or platter transplants. The main factors affecting data recovery costs are:

  • Type of failure
  • Drive size and model complexity
  • Cleanroom disassembly requirements
  • Amount of data to recover

Data recovery can be worth the high costs for truly valuable or irreplaceable data. But for more common data, backups are more cost effective than recovery. Preventing drive failures in the first place provides the most financial and data protection.

Can lost data be recovered without sending the drive to a professional recovery service?

It depends on the type and extent of the drive failure. Minor errors may allow DIY data recovery using software tools that can repair corrupted partitions or file systems. Examples include:

  • TestDisk
  • EaseUS Data Recovery Wizard
  • Stellar Data Recovery
  • Ontrack EasyRecovery

If the drive powers on and stays stable, these tools may recover data. But if electronics are damaged or platters/heads have failed, DIY software cannot extract data reliably from the drive hardware.

Opening up a portable drive outside a cleanroom risks contaminating the platters and makes professional recovery impossible. So while DIY recovery has limited usefulness, leave serious recovery attempts to professionals.

Can lost data be recovered from clicking, beeping or completely dead portable hard drives?

Clicking or beeping noises typically indicate a serious mechanical or electronic failure in the drive. Usually the drive motor, heads/actuators, controller board, or PCB components are damaged.

Complete drive failure with no power at all suggests an electrical issue, damaged PCB, or failed controller components.

Professional data recovery services can sometimes recover data from clicking, beeping or dead portable hard drives. This requires specialized cleanroom disassembly and component repair or replacement. However, the more extensive the hardware damage, the lower the chances of recovering data.


Portable external hard drives provide a handy means for storing, accessing, and transporting data. However, like all storage media they can and do fail at measurable rates.

To maximize reliability, handle portable drives gently, protect from shock/vibration, maintain proper operating conditions, and follow the manufacturer’s guidelines. Backing up important data provides an additional layer of protection against failure.

Overall, exercising reasonable care and following best practices allows users to gain productive and reliable use from portable external hard drive storage.