An external hard drive is a portable storage device that can be attached to a computer through a USB connection or wirelessly. External hard drives typically have high storage capacities and are often used to back up computers or serve as a network drive.
There are two main types of external hard drives: hard disk drives (HDD) and solid state drives (SSD). HDDs rely on mechanical moving parts like a disk platter to store and read data, while SSDs use microchips. Both have advantages and disadvantages in terms of speed, reliability, storage capacity, cost, and portability.
This article provides an overview of HDD and SSD external drives, comparing them across the key factors to consider when choosing an external hard drive. It aims to help readers understand the use cases for each drive type and decide which is better suited for their needs.
HDD (Hard Disk Drive)
HDD stands for Hard Disk Drive. It is a mechanical drive that uses spinning platters with magnetic surfaces to store data. The platters spin at high speeds while the read/write head moves over the surface to access data. HDDs have been around for decades and are a proven and mature storage technology.
Some key characteristics of HDDs:
- Use magnetic disks/platters to store data
- Movable read/write heads access the data
- Spinning mechanics make distinct noise when operating
- Slower than SSDs due to physical limitations
- Much cheaper per gigabyte compared to SSD
- Higher storage capacities available, up to 10TB+ for consumer models
HDDs are ideal for tasks like:
- Storing large volumes of data
- Backing up photos, videos, documents
- Archiving old files
- Any application where speed is not the top priority
In summary, HDDs are the traditional hard drive technology that offer high capacities at low costs, but are slower than SSDs.
SSD (Solid State Drive)
SSDs use flash-based memory and contain no moving mechanical parts, unlike traditional HDDs. This allows SSDs to be more durable and shock-resistant. The data is stored on interconnected flash memory chips that retain the data even when there’s no power present (Source: https://www.pcmag.com/picks/the-best-external-ssds).
Because there are no moving parts, SSDs are silent in operation and produce less heat. They also have faster access times due to not needing to physically move a disk platter like HDDs (Source: https://www.bestbuy.com/site/hard-drives/solid-state-drives/pcmcat201300050005.c?id=pcmcat201300050005). Overall, the lack of moving parts makes SSDs better suited for portable external storage.
Speed
SSDs are significantly faster than HDDs when it comes to data transfer speeds. SSDs use flash memory and have no moving parts, allowing them to read and write data very quickly. HDDs use spinning platters and moving read/write heads, making them much slower.
According to Avast, SSDs can copy files at speeds of 500 MB/s, while HDDs max out at around 150 MB/s. When loading programs and files, SSDs provide near instantaneous access, while HDDs can take several seconds. The lack of moving parts also makes SSDs better suited for mobile use where shocks and vibrations are common.
For tasks like gaming, video editing, and running demanding software, SSDs provide a noticeable speed advantage over HDDs. Their fast data access reduces load times and improves overall system responsiveness. HDDs are cheaper per gigabyte but are dramatically slower.
Reliability
SSDs are generally considered more reliable and durable than HDDs. SSDs have no moving parts, making them less susceptible to mechanical failures or damage from drops and impacts. Research by cloud storage provider Backblaze found SSDs to have an annualized failure rate of around 1% in the first four years of use, compared to a failure rate of 1.5-2% for HDDs over the same period.
Backblaze’s findings suggest SSD reliability is particularly advantageous in mobile computing devices that are prone to being dropped and transported. For most everyday computing uses and backups, SSDs carry a lower risk of sudden failures resulting in data loss.
Some factors impacting HDD reliability include warmer operating temperatures and the accumulating damage from drive heads repeatedly touching platters during operation over time. SSDs avoid these failure mechanisms entirely through their solid state design.
Storage Capacity
HDDs tend to have a higher maximum storage capacity compared to SSDs. While consumer HDDs are commonly available in sizes up to 10TB, the maximum capacity for consumer SSDs tends to top out at 4TB (SSD vs. HDD: What’s the Difference?). This is because HDDs use spinning platters that can fit more data per platter compared to SSDs which rely on microchips.
However, SSD capacities have been steadily increasing over time. While the maximum capacity is lower, most consumer SSDs still offer ample storage space for everyday use cases. For example, 500GB to 1TB SSDs are very common for laptops and desktops (SSD vs HDD: Which Do You Need?).
Where HDDs excel is in niche applications requiring enormous storage pools, like multi-terabyte server storage or archival backup repositories. The largest SSDs may top out at 16TB, while HDDs can reach capacities like 20TB for consumer drives and even higher for enterprise use.
Cost
HDDs are almost always much cheaper than SSDs with the same storage capacity. A Terabyte of HDD storage may run $35, versus $100 per TB for an SSD. This is because HDDs have been around much longer and have economies of scale, while SSD manufacturing is newer and more expensive.
For example, according to a price comparison chart on Reddit, in 2013 the most affordable SSDs cost around $625 per TB, while HDDs were around $60 per TB. So there is still a significant price difference between SSD and HDD storage.
Overall, HDDs provide much more affordable bulk storage, which makes them ideal for backup drives or archiving large media files. SSDs are more expensive per GB but provide much faster performance, making them better suited for boot drives or frequently accessed programs and files.
Sources:
As requested: An improved chart of SSD vs HDD historical and projected prices. SSD to reach price parity by 2030 if current trend continue.
byu/CokeZoro inDataHoarder
https://reviewed.usatoday.com/laptops/features/ssd-vs-hdd
Portability
When it comes to portability, SSDs have a clear advantage over HDDs. SSDs are lighter and much smaller in physical size due to having no moving parts. A typical 2.5″ SSD weighs around 1.5 ounces, while a 2.5″ HDD can weigh around 4-5 ounces. In terms of dimensions, a 2.5″ SSD is typically around 2.75″ x 3.96″ x 0.27″, while a 2.5″ HDD is around 3.94″ x 2.76″ x 0.37″.
This size and weight difference allows SSDs to be better suited for portable external storage. External SSDs can be palm sized and easily fit in a pocket. Portable external HDDs still require a case which adds bulk. The lightness of SSDs also makes them better for transporting without risk of damage due to shock. Overall, if portability is a priority, then an external SSD is the better choice over an external HDD.
Use Cases
When choosing between an HDD and SSD, it’s important to consider the use case. HDDs tend to be better suited for archival storage and backups due to their larger capacities and lower costs per gigabyte. SSDs are better for applications that require faster access like operating systems, games, or creative applications. Here’s an overview of some common use cases:
HDD Use Cases:
- Archival storage – Good for storing large amounts of “cold data” that doesn’t need frequent access like old photos, videos, documents, etc. HDDs offer larger capacities for lower costs.
- Backups – Good for regular backup of a computer’s contents. Speed is less critical for backups so the lower cost per gigabyte makes HDDs preferable.
- Media storage – Can store large media libraries of music, movies, photos. Access speed is less critical.
SSD Use Cases:
- Operating system drive – SSDs allow for much faster boot times due to the improved random read/write speeds.
- Primary applications – Programs will launch much quicker when installed on an SSD.
- Games – Games benefit from the reduced load times that SSDs provide.
- Content creation apps – Video/photo editing apps perform better with improved read/write speeds of SSDs.
In summary, HDDs work well for simply storing large amounts of infrequently accessed data due to lower costs. But for performance-critical applications, SSDs are preferable due to significantly faster read/write speeds.
Conclusion
In summary, the two main types of external hard drives are HDDs and SSDs. HDDs use spinning magnetic disks to store data and are generally cheaper and offer higher storage capacities. However, they are slower, less reliable, and more prone to damage from drops or shocks. SSDs use flash memory with no moving parts, making them faster, more reliable, and better for portable use. However, SSDs are typically more expensive and have lower maximum capacities.
When choosing an external hard drive, consider your budget, storage needs, and how you plan to use the drive. If you need lots of affordable storage and the drive will remain stationary, an HDD is likely the better option. If speed, reliability, and portability are important and you don’t require enormous amounts of storage, an SSD is likely the better choice.
To maximize the lifespan of your external hard drive, handle it with care, don’t expose it to liquids or extreme temperatures, create backups of your data, and follow the manufacturer’s recommendations for care and maintenance. With proper handling, both HDDs and SSDs can provide reliable external storage solutions.