With the constant improvement in solid state drive (SSD) technology and decline in prices over the last decade, many computer users face the decision of whether to upgrade from a traditional hard disk drive (HDD) to an SSD. SSDs provide substantial performance and reliability benefits over HDDs, but cost more per gigabyte of storage. This article examines the key differences between SSDs and HDDs and analyzes the pros and cons to determine if SSDs are worth the higher price for most users.
SSD and HDD Technology Comparison
SSDs and HDDs store data using completely different methods, which accounts for major performance differences. An HDD uses magnetic disks called platters that spin at high speeds while a read/write head moves over the surface to access data. This mechanical operation leads to moving parts that reduce reliability and cause slower access times due to physical motion requirements.
In contrast, an SSD has no moving parts and instead stores data in flash memory chips made up of billions of interconnected transistors called NAND cells. Reading data simply requires applying voltage to the cells, allowing nearly instantaneous data access without physical motion. This fundamental difference in technology gives SSDs substantial advantages in performance, power efficiency, and reliability.
Speed
The most noticeable advantage of an SSD over an HDD is the incredible speed improvement. SSDs have almost zero latency, meaning there is no seek time for the drive head to get into position before reading or writing data. This gives SSDs orders of magnitude faster access times compared to HDDs.
For sequential read/write operations when accessing large files, SATA SSDs can reach sustained speeds of around 500-550 MB/s, while HDDs max out at around 100-200MB/s. The advantages are even more substantial for random access operations that read small chunks of data from different locations. SSDs can handle hundreds of thousands of random read/write IOPS (input/output operations per second), while HDDs manage only hundreds of IOPS for random access.
Reliability and Durability
With no moving parts, SSDs are more rugged and resistant to failure from shock or vibration. Dropping a laptop with an SSD has minimal risk of losing data, while a traditional HDD could easily fail from damage to the physical platters and heads. SSDs are generally safer for mobile computing applications.
Additionally, SSDs are not hurt by magnetism and have higher tolerance for extreme temperatures. Overall, SSDs can withstand more harsh physical environments and keep working well past the life expectancy of comparable HDDs. However, HDDs still outlast SSDs when it comes to total bytes written over the lifetime of the drive. The cells in flash memory can only be overwritten a finite number of times before wearing out.
Power Efficiency
The basic operation of SSDs consumes much less power than HDDs, giving SSDs a clear efficiency advantage. Spinning platters in HDDs require more energy to rotate at high speeds compared to the low power needed for SSDs to read electronic signals from NAND cells. This makes SSDs better suited for laptops and mobile devices where battery life limitations exist. The lower energy draw also creates lower heat output and less need for cooling fans in computers equipped with SSDs.
Noise
With no moving parts, SSDs are completely silent. The physical clatter from HDD platters and heads is eliminated, which can be extremely beneficial in quiet computing environments. Noise is often an overlooked factor when comparing drives, but the audible difference is quite dramatic for PCs that need to operate quietly.
Size and Weight
The chips and circuit boards used in SSDs take up much less physical space than HDD mechanisms, allowing SSDs to have much smaller form factors. SSDs in laptops help create thinner mobile computing designs. For desktop PCs, SSDs also weigh less because they lack bulky drive housings and heavy platters. The absence of moving parts again contributes to the compact and lightweight advantages of SSDs.
SSD and HDD Cost Comparison
The biggest tradeoff between SSDs and HDDs comes down to dollar-per-gigabyte cost. HDDs are far cheaper in terms of storage capacity per dollar spent compared to SSDs. As of 2019, good SATA SSD deals may reach around 15-20 cents per gigabyte, while large HDDs can be purchased for 3-5 cents per gigabyte. The price gap has narrowed recently but HDDs still offer more value from a pure storage capacity angle.
However, looking only at dollar-per-gigabyte cost ignores the performance benefits of SSDs versus HDDs. While a 1TB HDD and 1TB SSD both give you 1TB of storage, the SSD delivers that storage with far higher speed, better reliability, and power efficiency advantages. For tasks like operating system and program loading, the technical capabilities of SSDs justify the higher cost premium.
Here is a comparison of example SSD and HDD drives around $100 each as of late 2019:
| Spec | SSD (SATA) | HDD (SATA) |
|---|---|---|
| Price | $100 | $100 |
| Capacity | 500GB | 2TB |
| Max Sustained Read Speed | 550 MB/s | 190 MB/s |
| Max Sustained Write Speed | 520 MB/s | 180 MB/s |
| Random Read IOPS | 90,000 | 150 |
| Random Write IOPS | 90,000 | 150 |
This illustrates the large performance advantages SSDs provide despite the much higher storage capacity available from the HDD. Each drive type has merits, so it comes down to matching the strengths of SSDs and HDDs to your computing needs and budget.
Primary SSD and HDD Pros and Cons
Here is a summary of the major advantages and disadvantages when comparing SSDs and HDDs:
SSD Pros
- Faster sequential read/write speeds, remarkably faster random access
- More reliable with less risk of failure due to shock or vibration
- Lower power consumption and less heating
- Completely silent operation
- Smaller and lighter for portable computing needs
SSD Cons
- More expensive per gigabyte
- Lower total storage capacities available
- Limited number of writes before wearing out (improving with newer technology)
HDD Pros
- Much cheaper per gigabyte
- Higher maximum storage capacities
- Can withstand more total bytes written over lifetime
HDD Cons
- Slower sequential and dramatically slower random access speeds
- More prone to failure from shocks and vibration
- Higher power consumption and heating
- Audible noise during operation
- Larger and heavier, less suited for portability
Should You Upgrade from HDD to SSD?
When considering upgrading an existing computer from HDD to SSD, there are several factors to help determine if it is worthwhile:
- Operating System Drive – An SSD is highly recommended for the drive where your operating system is installed. This takes best advantage of the SSD performance benefits for faster booting and launching programs.
- Frequently Used Applications – Programs you use all the time see large benefits from being installed and run on an SSD due to the speed boost.
- Scratch Disks for Content Creation – For photo, video, and audio editing the SSD can provide a snappier workflow.
- Notebook Computers – The power efficiency and durability make SSDs ideal for laptops that get moved around a lot.
- Gaming PCs – Quick level loads and reduced texture pop-in are perks when running games from an SSD.
- Noise Reduction – An SSD upgrade eliminates annoying HDD noise for a quieter PC.
For general home and office use where you mainly browse the web, check email, and use basic applications the benefits may be less noticeable when weighed against the SSD cost premium. But for most power users and specialized applications, upgrading to an SSD as the primary drive is recommended to gain the speed and responsiveness improvements.
SSD and HDD Ideal Usage Examples
Due to the performance and cost differences it makes sense to use SSDs and HDDs for different purposes in a computer for an optimal setup.
Ideal Uses for SSDs
- Primary internal drive for operating system and programs
- Additional internal drives for games and performance-hungry applications
- External portable storage when smaller size and durability are needed
Ideal Uses for HDDs
- Media storage for music, videos, photos, and other large files
- Backup drive for system images and data archives
- Additional internal data storage drive
- External desktop storage when capacity is key and portability is not needed
Many PC power users gravitate toward a dual drive setup with an SSD as the primary OS and applications drive paired with a large HDD for data storage. This allows you to take advantage of both technologies to maximize performance and storage capacity.
Conclusion
SSDs provide huge performance and reliability gains over traditional HDDs by leveraging faster solid state memory and no moving parts. The dramatically quicker speeds of SSDs make a clear difference for booting operating systems, launching programs, saving files, and loading game levels. For everyday computer use for work, school, or entertainment, switching to an SSD vastly improves general computing responsiveness.
SSDs do cost more per gigabyte than HDDs, so higher storage capacity drives still favor the HDD. But with the continuing fall in SSD prices, the speed and reliability benefits make SSDs worth the premium over HDDs for most computing needs. In nearly all cases, purchasing a computer with an SSD as the primary drive is well worth it over sticking with just an HDD.