There are a few key differences between a solid state drive (SSD) and a traditional hard disk drive (HDD) that are worth considering when deciding whether you need an SSD in addition to an HDD. While HDDs have been the standard for many years, SSDs are gaining popularity due to their faster speeds and reliability. This article will examine the pros and cons of each to help you determine if adding an SSD is right for your needs.
What is a Hard Disk Drive (HDD)?
A hard disk drive (HDD) is a traditional storage device that has been widely used for decades. It contains spinning platters and a read/write head to access data. Here are some key attributes of HDDs:
- Slower sequential read/write speeds – HDDs can read and write data sequentially at around 100-200 MB/s.
- Mechanical components – The moving parts of HDDs make them susceptible to damage from drops or vibration.
- Lower cost per gigabyte – HDDs are affordable at around $0.03 per GB for consumer models.
- Higher capacity options – HDD capacities range from 40GB to 12TB for desktop models.
The mechanical nature of HDDs causes them to be slower and more prone to failure compared to SSDs. But their lower cost makes HDDs ideal for mass storage of files that don’t need quick access.
What is a Solid State Drive (SSD)?
A solid state drive (SSD) is a storage device that uses flash memory instead of spinning platters. Here are some key attributes of SSDs:
- Faster sequential read/write speeds – SSDs can read and write data sequentially over 500 MB/s up to 5,000 MB/s for high-end models.
- No moving parts – The lack of moving parts makes SSDs resistant to physical damage.
- Higher cost per gigabyte – SSD pricing starts around $0.20 per GB for consumer models.
- Lower capacity options – SSD capacities range from 120GB to 8TB for consumer desktop models.
The pure electronic nature of SSDs allows for incredible speed and reliability. But the higher cost per gigabyte means SSD capacity maxes out lower than HDDs.
Comparing HDDs vs. SSDs
|Attribute||Hard Disk Drive (HDD)||Solid State Drive (SSD)|
|Sequential read/write speed||100-200 MB/s||Over 500 MB/s up to 5,000 MB/s|
|Random read/write speed||~10-200 IOPS||Up to 600,000 IOPS|
|Durability (MTBF)||1-2 million hours||1.5-2.5 million hours|
|Power consumption||5-10 Watts||2-4 Watts|
|Cost per GB||$0.03 per GB||$0.20+ per GB|
|Capacity||40GB to 12TB||120GB to 8TB|
This comparison shows that SSDs are significantly faster in sequential and random read/write speeds. Their lack of moving parts also makes them quieter, more power efficient, and a bit more durable. However, HDDs are much cheaper per gigabyte and offer higher maximum capacities.
Benefits of Adding an SSD
Given their differences, here are some of the key benefits you can gain by adding an SSD to complement an existing HDD setup:
Faster boot and load times
Installing your operating system and frequently used programs like browsers on an SSD can dramatically speed up boot and load times. While an HDD may take 30-60 seconds to boot, an SSD can cut that time down to 10-30 seconds.
Faster file transfers
Copying or moving files between drives or networks shares will be significantly faster with an SSD. Large file transfers that take minutes with an HDD can complete in seconds with an SSD.
Faster access to frequently used files
Files you access often like documents, photos, downloads and games will load much quicker when stored on an SSD versus an HDD. No need to wait for mechanical platters to spin up.
Improved workflow for read/write intensive tasks
Applications that involve heavy file reading/writing like video editing, 3D rendering or data analysis will see meaningful workflow improvements from running on an SSD scratch disk.
More reliable in harsh environments
The lack of moving parts makes SSDs better suited for mobile use where vibration or drops are likely. Their lower power draw also makes them suitable for devices with smaller batteries.
Downsides of SSDs
SSDs aren’t perfect, here are some downsides to weigh:
Higher cost per gigabyte
SSDs are priced significantly higher than HDDs per gigabyte. You can get 8TB HDDs around $150 while a 2TB SSD costs over $200. So if you need high capacities, HDDs are much more economical.
Lower maximum capacities
While HDDs now offer up to 12TB consumer models, most SSDs max out at 8TB. If you have high storage needs, HDDs can offer larger single drive capacities.
Degraded performance over time
SSDs can slow down over time as memory cells wear out. However most quality SSDs will continue performing well for daily consumer workloads long beyond their warranties.
Potential data loss with power loss
SSDs temporarily store data in memory before writing to flash storage. Sudden power loss can cause data corruption or loss if in-transit data isn’t all written to the drive.
Typical SSD + HDD Configurations
Here are some typical setups that balance SSD speed with HDD capacity:
Boot drive SSD + high capacity HDD
Install your operating system and most used programs on a 250GB-500GB SSD. Use a larger 4TB+ HDD for storing personal files like documents, photos, videos and games.
Dual drive SSD + mid-size HDD
Combine a 500GB+ SSD for booting and programs with a 2TB HDD for personal storage. Gives you speed along with ample capacity for most users.
External SSD USB drive
Use a portable external SSD up to 2TB via USB for transferring files or as a scratch disk for intense projects. Then store everything else long term on HDD.
M.2 NVMe SSDs
M.2 SSDs that use PCIe NVMe interfaces offer the fastest SSD speeds available today. Here are some benefits of M.2 NVMe SSDs:
- Sequential read/write over 3,000 MB/s
- Up to 600,000 IOPS random read/write
- Low latency for reduced load times
- Smaller form factor to fit space constrained PCs
Downsides of M.2 NVMe SSDs include maximum capacities of 2TB for consumer models currently. They also require your PC to have an M.2 slot and support NVMe bootability. But for pure speed, M.2 NVMe SSDs are the fastest option.
When an SSD Makes Sense
Here are some common situations where adding an SSD can benefit overall system performance:
- Slow boot and program launch times
- Upgrading an older PC
- Running intensive applications like video editing, 3D modeling, engineering software
- Working with large files like high-res photos and videos
- Console storage upgrades to improve game load times
- Frequent file transfers over network or drives
For general web browsing, office work and lighter computing an SSD may provide less noticeable improvements. But their speed advantages excel at demanding workloads.
SSDs provide big speed advantages over HDDs which can directly improve performance doing intensive computing or working with large files. An ideal setup is pairing an SSD with an HDD, using the SSD for your operating system, apps, active projects and frequent files. Meanwhile the HDD offers abundant cheap storage for everything else. For demanding workloads or to give an older PC new life, adding an SSD alongside your existing HDD can provide a valuable performance boost.