How should you use SSD and HDD?

With the increasing popularity of solid state drives (SSDs), many wonder if hard disk drives (HDDs) are still useful. The answer is yes – HDDs and SSDs both have benefits depending on your storage needs. We’ll compare HDDs vs SSDs on key factors like speed, lifespan, and cost efficiency to help you decide when to use each.

What is the difference between an SSD and HDD?

SSDs and HDDs store data, but they use different technologies that impact their performance.

HDDs use spinning magnetic disks to store data. Data is written and read using an actuator arm with a read/write head that moves over the disk surface. The spinning disks allow sequential data access, meaning HDDs can read and write data stored in nearby locations on disk very quickly.

SSDs use flash memory chips to store data digitally. With no moving parts, SSDs use microchips. This allows for faster random access time to read and write data in any location in the memory. However, SSDs usually offer less overall storage capacity compared to HDDs for a similar price.

When should you use an SSD?

SSDs excel at fast data access speeds and are best for use cases like:

  • Boot drives: OS and programs load faster when installed on an SSD, usually in under 30 seconds instead of minutes.
  • Frequently used applications: Games, creative programs like photo/video editors see faster load and save times.
  • Mission critical data: Financial records, medical images, engineering data need fast and reliable access.

SSDs are ideal as your primary storage or for storing data that needs quick access. The speed advantages are very noticeable for typical consumer use. The downsides are higher cost per gigabyte compared to HDDs and limited lifespan due to memory cell wear.

When should you use an HDD?

HDDs are better suited for data that doesn’t need fast access, but where large capacity cheap storage is important, such as:

  • Archive data: Older files, backups, raw footage that doesn’t need frequent access.
  • Large media libraries: Photos, videos, music when capacity is more important than speed.
  • Gaming: Can store large games when speed is less critical. SSD for active games.

HDDs are significantly cheaper per terabyte compared to SSDs. The maximum capacities are higher as well. Downsides are slower access speeds and higher failure rates due to moving parts. HDDs also consume more power for data access.

SSD vs HDD Speed Comparison

SSD and HDD speeds can differ substantially. Comparing max theoretical speeds of the interfaces gives an idea of the huge speed advantage of SSDs:

Storage Type Interface Max Speed
SATA SSD SATA 3.0 600 MB/s
NVMe SSD PCIe 3.0 x4 3.5 GB/s
HDD (7200 rpm) SATA 3.0 210 MB/s

Actual real world speeds will be lower, but SSDs will outpace HDDs significantly. Even a SATA 3.0 SSD can be over 2x faster than a fast HDD. Upgrading to an NVMe SSD makes the speed difference even more extreme, with 3.5 GB/s theoretical transfer rates.

Reasons for speed advantage

SSDs have faster access speeds than HDDs because:

  • No moving parts – data access does not rely on physical component movement
  • Non-sequential access – memory chips allow randomly accessing data fast
  • Lower latency – data retrieval starts faster
  • Faster interface – SATA 3.0 and especially PCIe NVMe provide more bandwidth

For typical consumer workloads, SSDs can provide at least a 2-4x speedup in booting and loading applications and files compared to HDDs. For processors and GPUs that need constant data, the low latency of SSDs is extremely beneficial.

SSD vs HDD Reliability

SSDs have fewer points of failure with no moving parts and therefore lower failure rates than HDDs. However, SSDs do experience declining performance and uneven wear as memory cells degrade after extensive usage. HDDs fail unpredictably but sudden mechanical failures are more likely.

SSD Reliability Advantages

  • No moving parts, making physical failure unlikely
  • Resistant to shock, vibration, temperature
  • Lower failure rates (1.5% vs 2.5% annualized)
  • Silent operation and low power usage

SSD Reliability Disadvantages

  • Write amplification wears cells unevenly
  • Memory cell degradation over time
  • FILEystem and controller errors possible
  • Unexpected write failures may occur

HDD Reliability Advantages

  • Long established technology, well understood
  • Gradual predictable performance decline

HDD Reliability Disadvantages

  • Fragile moving parts prone to sudden failure
  • Vulnerable to vibration, shock, contamination
  • Loud mechanical operation
  • Higher failure rates and unpredictability

Overall SSDs have the reliability advantage for most usages, although ultimate longevity under very heavy write loads may favor HDDs. Both can benefit from redundancy via backups and RAID configurations to minimize downtime.

SSD vs HDD Cost Comparison

SSDs continue to command a price premium over HDDs for the same storage capacity. However, the cost gap has narrowed over the years. As of 2022, 1 TB SSDs start around $75 while 1 TB HDDs are $30 or less.

Some cost comparisons for consumer models:

Drive Type Capacity Price Cost Per GB
SATA 2.5″ SSD 1 TB $75 $0.075
SATA 3.5″ HDD 1 TB $30 $0.03
SATA 2.5″ SSD 2 TB $140 $0.07
SATA 3.5″ HDD 2 TB $50 $0.025
NVMe M.2 SSD 1 TB $100 $0.10
SATA 3.5″ HDD 4 TB $80 $0.02

While HDDs are around 2-3x cheaper than SSDs per gigabyte, remember that SSD provide a speed advantage that can justify the premium for many users. Paying more upfront for an SSD with your OS and apps can give you a much snappier computer experience.

Factors impacting cost

Several factors contribute to the pricing differences:

  • Manufacturing: HDD technology is mature and optimized over decades. SDD production has scaled up but is a newer technology.
  • Components: SSDs require expensive NAND flash chips, while HDDs use inexpensive spinning disks.
  • Supply and demand: HDD supply is plentiful, while SSD NAND flash supply can have shortages.
  • Capacity: SSD capacities still range from 128GB to 4TB for consumers, while HDDs go from 320GB to 16TB.

Over time, analysts expect SSD prices will continue to decline and reach parity with HDDs in cost per gigabyte sometime in the next decade.

Ideal uses for SSDs

SSDs are well suited for uses that require fast data access and responsiveness, where their performance advantages over HDDs are worthwhile even at a higher initial cost. Common uses include:

  • Primary system drive: Boot and application load times will be significantly faster.
  • Gaming: Level load times accelerated. Game installs and updates faster.
  • Creative work: Faster access to project files and scratch disks for video/photo editing.
  • Application workloads: Data analysis, engineering, financial modeling see speedups.
  • External portable storage: Excellent durability if device is moved or dropped.

For your primary drive, an SSD is highly recommended as a worthwhile upgrade over an HDD. The system responsiveness improvement is very noticeable. Use larger capacity HDDs for storing files that don’t need quick access.

Ideal uses for HDDs

HDDs are better suited for data that doesn’t require fast access, where sheer capacity and storage density is more important than speed. HDDs are cost efficient for:

  • File backups and archives: Historical records, old family photos can use cheap HDD storage.
  • Media libraries: Large collections of music, movies, TV recordings.
  • Gaming storage: Can store a large Steam library or other games you play infrequently.
  • Home NAS: Centralized storage for backup, media, documents accessed on a home network.
  • General external storage: Lower cost per TB makes HDDs appealing for additional capacity.

For these uses, HDDs are likely the more economical choice to maximize storage capacity. Just keep in mind they come with slower access speeds depending on use cases.

How should you combine SSD and HDD storage?

The ideal setup for many is using both an SSD and HDD together to get the best performance and high capacity:

  • SSD: Primary internal storage for OS, applications, games that benefit from speed.
  • HDD: Secondary internal storage for media, documents, other files.
  • External HDD: Optional affordable backup and extra capacity.

With this arrangement, you get fast boot and load times thanks to the SSD. Larger capacity HDD storage allows you to still keep lots of files handy on the faster internal drive rather than external storage. Backing up to an external HDD provides redundancy if anything happens to your primary drives.

Balance your budget and storage needs – adding a 1 TB SSD for your OS and apps combined with a 2 TB HDD for secondary storage offers great performance and capacity for most at reasonable costs. Go bigger on the HDD if you need more room for videos, photo collections, etc.

SSD and HDD Upgrades

Upgrading an existing HDD setup to add an SSD or upgrading from a smaller to larger SSD are straightforward processes, but require reinstalling your operating system and programs onto the new drive.

Upgrade considerations

  • Use disk cloning software to migrate data over initially.
  • Clean install the OS and apps on the new drive.
  • Keep the old HDD for data storage reuse.
  • External enclosures can reuse old HDDs as external drives.
  • Clone HDD contents or clean install to a larger new HDD.
  • An external SSD adds fast portable storage.

Consult your motherboard manual for proper installation steps when adding a second drive. Ensure you purchase compatible SSD or HDD types – M.2 and 2.5″ drives for laptops or desktops, SATA or NVMe SSDs depending on board support.


SSDs and HDDs each have advantages in speed, capacity, longevity, and cost that make them suited for different storage needs. For most consumers, combining a speedy SSD with enough capacity for your operating system, apps, and active projects together with a lower cost high capacity HDD for additional storage provides an ideal balance of performance and value.

Leave a Comment