Is external SSD more reliable than flash drive?

With the increasing need for external storage devices, external solid state drives (SSDs) and flash drives have become very popular. Both devices allow you to store and transfer data, but which one is more reliable for long-term data storage? In this comprehensive guide, we’ll examine the differences between external SSDs and flash drives, look at the pros and cons of each, and help you determine which is the better choice for your needs.

What is an External SSD?

An external SSD is a type of solid state drive that is portable and plugs into your computer externally, typically via USB. Like an internal SSD, it uses flash memory instead of a spinning hard disk for storage. However, external SSDs are encased in a durable outer casing to protect the internal components from damage.

External SSDs offer incredibly fast data transfer speeds, often up to 550MB/s for reads and up to 500MB/s for writes when using a USB 3.2 Gen 2×2 port. This is significantly faster than external hard disk drives (HDDs) and flash drives. The fast speeds are enabled by the flash memory and connection interfaces used in external SSDs.

Additionally, external SSDs are far more durable and resistant to shocks and vibrations compared to external HDDs. The lack of moving parts means there are no small mechanical components that can fail or get damaged. SSDs are better optimized for travel and on-the-go use.

Benefits of External SSDs

  • Faster transfer speeds than HDDs and flash drives
  • More durable and resistant to shock
  • Lower power consumption
  • Compact, lightweight and portable
  • Makes less noise and stays cooler
  • Often has larger capacity than flash drives

What is a Flash Drive?

A flash drive, also known as a USB drive, is a small storage device that uses flash memory and connects to devices via USB port. It doesn’t require an external power source and gets power supply directly from the USB port.

Flash drives are available in capacities ranging from 1GB to 1TB. Lower capacity drives have slower transfer speeds, while higher capacity ones boast speeds up to 250MB/s read and 100MB/s write speeds when using USB 3.2 Gen 1 connectivity.

Due to their compact size and plug-and-play functionality, flash drives are extremely portable and convenient for transferring files between different devices. They are commonly used for storing documents, photos, videos and other media files.

Benefits of Flash Drives

  • Small, compact and highly portable size
  • No need for external power supply
  • Very convenient plug-and-play functionality
  • Cheaper than external SSDs
  • Compatible with most computers and devices

Reliability Comparison

When it comes to reliability for long-term storage, external SSDs tend to outperform flash drives. Here’s a detailed comparison of factors affecting the reliability of both options:


Due to lack of moving parts, external SSDs are far more resistant to damage from shock, vibrations and accidental drops. They are built for portability and can withstand a higher degree of abuse. Flash drives have internal chips and components that can get damaged easier if dropped or mishandled.

Data Retention

External SSDs generally have a longer data retention period than flash drives. The data on an SSD can last for up to 10 years without degradation. However, low-quality flash drives may start losing data in as little as a year.

Rewrite Cycles

The memory cells in SSDs are rated for a higher number of rewrite cycles before failure, compared to flash drives. Most external SSDs today are rated for 1500 to 3000 rewrite cycles. Flash drives are typically rated for 500-1000 rewrite cycles.


External SSDs often come with AES 256-bit or equivalent hardware-level encryption to provide an added level of data security. Encryption capabilities in flash drives can vary, with lower-end models having no encryption.

Failure Rate

Enterprise-class external SSDs have an annual failure rate (AFR) of around 0.5-0.8%, meaning less than 1% devices can be expected to fail per year. In comparison, flash drives have a higher AFR of around 1.5-2%.

Temperature Tolerance

Due to lack of moving parts, SSDs function at a broader temperature range and operate better in extreme heat or cold conditions. Flash drives are more prone to performance degradation or failure when used outside their optimal temperature range.

Reliability Factor External SSD Flash Drive
Durability Very high Moderate
Data Retention Up to 10 years 1-5 years
Rewrite Cycles 1500 to 3000 500 to 1000
Encryption Often 256-bit AES Variable support
Failure Rate 0.5% to 0.8% AFR 1.5% to 2% AFR
Temperature Tolerance Very high Moderate

Why External SSDs are More Reliable

Based on the above comparison, external SSDs are more reliable for long-term data storage due to the following key reasons:

Superior Build Quality

External SSDs feature better build quality with more rigid, shock-resistant enclosures to protect the internal components. They can withstand accidental drops and shakes which can damage flash drives.

No Moving Parts

The absence of moving parts like the spindle motor and platters found in HDDs eliminates key points of failure. External SSDs are not prone to issues like disk wear and mechanical breakdown.

Lower Failure Rates

The typical annual failure rate seen in enterprise-grade external SSDs is very low at 0.5-0.8%. Consumer-grade flash drives tend to have higher failure rates of around 1.5-2% per year.

Sophisticated Error Correction

Advanced error checking and correction technologies used in SSDs enhance the integrity of stored data and reduce the likelihood of errors accumulating over time.

More Stable Storage Medium

NAND flash memory offers more stable long-term storage compared to the flash memory in lower-end USB drives which can deteriorate faster.

Wider Temperature Tolerance

SSDs work reliably across a broad temperature range whereas flash drives are optimized for a narrower range of ambient temperatures for stable operation.

Better Datalife and Health Monitoring

Many external SSDs today come with advanced datalife monitoring technology to estimate drive lifespan based on actual usage. They also have smarter sensors to monitor drive health.

Use Cases and Recommendations

Based on the differences covered so far, here are some guidelines on when an external SSD or flash drive would be most suitable:

  • External SSDs are recommended for frequently accessed files and programs where fast speeds are needed. They excel as boot drives and additional storage for PCs.
  • For simply transferring occasional files between devices, a flash drive is fine. The slower speeds and lower capacities are less of an issue here.
  • For backing up essential data and documents that need long term archiving, an external SSD provides more reliable storage.
  • If you need to physically share files by passing around the drive, a flash drive is more compact and convenient.
  • For video editing, animation, gaming and other disk intensive work, an external SSD will provide much better performance.

Cost Considerations

External SSDs carry a significant cost premium over flash drives. Here are some points to factor in:

  • Consumer-grade flash drives can be found for under $10 for 64GB, whereas external SSDs start at around $80 for a 500GB model.
  • On a per-gigabyte cost comparison, flash drives are around 4-5 times cheaper than external SSDs.
  • Write speeds and durability come at a premium – you’ll pay more for an external SSD but get better features.
  • With flash drive costs being minimal, you can buy multiple flash drives as backups in case one fails.
  • If your usage requires moving large files frequently, the faster transfer rates of SSD save time and improve productivity.


In summary, while flash drives are more affordable, external SSDs are undoubtedly the superior choice for applications requiring reliable and fast external storage. Their durability, lower failure rates, temperature tolerance and sophisticated error correction technologies make them ideal for frequently accessed files and long-term storage needs.

For simply transferring occasional files between devices and sharing content physically, a flash drive gets the job done at a much lower price point. Just be prepared to replace them every 1-2 years and keep backups if storing anything critical.

So evaluate your specific usage needs and decide whether it’s worth investing in the added reliability and performance of an external SSD over a basic flash drive. The SSD premium delivers tangible benefits for the right kind of user and use case, but may be overkill for relatively casual storage requirements.


Is external SSD as fast as internal SSD?

The maximum speeds offered by the fastest external SSDs nearly match those of internal SSDs. For example, USB 3.2 Gen 2×2 drives can reach 2000MB/s read and write speeds, on par with PCIe 4.0 internal SSDs. However, real-world speeds are typically lower due to sharing bandwidth with the computer’s main processor and other factors.

Is it OK to keep external SSD plugged in all the time?

Modern external SSDs are designed to be plugged continuously without harming longevity or reliability. However, it’s recommended to eject the drive properly before unplugging it to prevent risk of file system corruption or data loss.

Do SSDs fail suddenly or slowly over time?

SSDs rarely fail suddenly without warning. Performance usually degrades gradually first as individual memory cells wear out. The drive will continue working at lower speeds before finally stopping when a critical number of bad cells accumulate. Monitoring tools can indicate declining health.

How do I diagnose and fix external SSD not detected issue?

If your external SSD is not being detected, try these steps:

  1. Plug the SSD into a different USB port and check if it’s detected.
  2. Try connecting the drive on a different computer.
  3. Reboot your computer and reconnect the SSD.
  4. Update USB and chipset drivers on your system.
  5. Check if the USB cable is loose or damaged.
  6. Try a different USB cable if available.

If the issue persists, your external SSD may be damaged and require professional data recovery assistance.

How long do external SSDs last compared to HDDs?

SSDs have a longer lifespan than hard disk drives (HDDs) under typical usage:

  • External HDD lifespan is around 3-5 years due to mechanical wear and tear.
  • External SSDs can reliably last up to 10 years with gradual slowdown beyond that.
  • Heavy workloads and frequent overwriting data reduces lifespan for both.

Proper care and avoiding extreme temperatures extends longevity for external drives. But SSDs inherently last longer than HDDs on average.