HDD vs SSD: Which one is better? The answer depends on the type of storage needed, the storage capacity, and the need for faster speeds. In this article, we’ll help you understand the key difference that can help you decide which one you choose.
A (Very) Brief History of Data Storage
Hard drives have been around since the 1950s and have evolved over time from using large platters to store a small amount of data to using smaller platters with higher capacity. The form factor and interface for connecting hard drives to computers has also changed over time.
Solid state drives (SSDs) are a newer type of storage that uses flash memory and does not require constant power to retain data.
They started appearing in laptops in the late 2000s and have since come in various form factors, including the 2.5-inch form factor and the M.2 format. SSDs have also increased in capacity and are now commonly used in both laptops and desktop computers.
What Is an HDD?
An HDD (hard disk drive) is a type of data storage device that uses spinning disks with magnetic surfaces to store data. It has an arm with transducers that move across the surface of the disks to read and write data.
HDDs are an older technology than SSDs (solid state drives) and are generally less expensive.
They are typically used to store data that does not need to be accessed frequently, such as backups. HDDs come in two common form factors: 2.5 inches, commonly used in laptops, and 3.5 inches, used in desktop computers.
What Is an SSD?
SSDs (solid state drives) are data storage devices that use solid state devices, such as integrated circuits, to store data.
They are smaller and faster than HDDs (hard disk drives) because they do not have spinning disks.
SSDs come in various sizes and capacities, making them suitable for smaller devices like laptops and tablets. They are generally more expensive than HDDs (cost per gigabyte of storage), but the price difference is decreasing.
How do hard disk drives (HDDs) work?
An HDD (hard disk drive) is a type of data storage device that uses spinning disks with magnetic surfaces to store data. The disks, also known as platters, are divided into sectors, which are further divided into bits that can accept an electrical charge.
When data is written onto the HDD, it is stored in the form of an electrical charge in the bits. The read/write head, which is part of an arm that moves across the surface of the platters, reads the charges and translates them into binary data (1s and 0s). Over time, the sector layout on the platters has changed to increase capacity.
The original method, called longitudinal recording, aligned the sectors horizontally, but this became a problem when the sectors were shrunk to increase capacity. To solve this problem, the perpendicular recording method was developed, which stacks the sectors on their ends, increasing capacity but making the HDD more sensitive to magnetic fields.
When a CPU writes data onto the HDD, it is written to the next available sector. Deleting old files and re-using their sectors can cause that the written data will stored in non-continuous areas (not sectors following each other sequentially).
This can lead to data separation, known as disk fragmentation, which can slow down access to the data. Most operating systems have a built-in program to defragment the HDD and rearrange the storage space for faster access.
Benefits of Hard Disk Drives (HDDs)
HDDs have been around for decades for good reason. They have advantages that continue to make them useful even though SSDs are becoming far more widespread. Here is a quick summary of their advantages:
- HDDs have a high capacity, with some models shipping with 20 TB of storage. They are also widely available with 250 GB of storage as standard in laptops and desktop PCs.
- HDDs have good performance, but the physical components of the device can create limitations, such as a slower boot-up time due to the slower access of each sectors.
- The lifespan of an HDD under constant use is three to five years, but it can be longer for external drives stored in a controlled space.
- HDDs do not suffer from wearout, as the number of overwrite passes of each sectors is not limited. This makes hard disk drives more ideal for applications with intensive data writes, for example video recording (DVR) recording environments.
- External portable HDDs have the same basic functions as internal HDDs and can be used with laptops or desktop computers. Internal HDDs can be also moved between devices, but are less compatible and require more effort to be transferred.
- HDDs are the most affordable storage type because they have a low cost per gigabyte. As storage capacity increases, the price of smaller HDDs decreases.
How do solid state drives (SSDs) work?
Solid state drives (SSDs or referred as flash storage) use electronic circuits to store and retrieve data. They use NAND (Not AND) logic gate flash memory, which consists of non-volatile transistors that store data as charges in semiconductors on silicon memory chips. The memory chips can be stacked to increase capacity, and the number of bits stored per cell affects the cost and durability of the SSD. Controllers manage the flash memory cells and handle data distribution and garbage collection.
SSDs can cache data for faster access and have lower power consumption than HDDs (hard disk drives) because they have no moving components.
The stored information periodically needs to be refreshed (re-programmed) which is done automatically by the internal SSD controller when the device is powered.
Benefits of Solid State Drives
Now we can compare the benefits of SSDs vs HDDs. Here are some simple bullet points to explain why many people now prefer SSDs:
- The capacity of SSDs (solid state drives) is increasing, with some models offering up to 8 TB and others as large as 100 TB. HDDs (hard disk drives) can have a capacity of up to 20 TB.
- As there are no moving heads, SSDs require no time to seek (position) to a data sector. SSDs offer faster access times and transfer speeds than HDDs: SATA SSDs can work up to 600 MB/s while NVMe M.2 SSDs can perform between 2000-6000 MB/s compared to 500 MB/s for fastest HDDs. SSDs offer faster file transfer and copying times.
- SSDs have a shorter lifespan and are less reliable for long-term storage compared to HDDs. They can also lose effectiveness as they approach their maximum terabytes written (TBW). Here’s a quick guide on how to check the health of an SSD.
- Both SSDs and HDDs can be portable, with external versions available for both. SSDs are useful for fast data transfer, while HDDs are better for long-term storage.
- SSDs are more expensive than HDDs on a per gigabyte basis, but the price gap is closing. SSDs are better for frequently used data and fast data retrieval, while HDDs are more cost-effective for larger capacities and long-term storage.
So, which one is better? Let’s look at a brief summary of their advantages and disadvantages.
HDD vs SSD – Summary of the Advantages and Disadvantages
Hard disk drives (HDDs) are a proven and cheap technology for storing large amounts of data. They are significantly less expensive per gigabyte than solid state drives (SSDs), and manufacturers have continued to improve their capacity and reduce costs.
However, HDDs produce noise, sensitive to mechanical damages/shock and are slower than SSDs. They are also mechanical devices that will wear out over time.
Despite these drawbacks, HDD technology has advanced significantly, with techniques such as replacing air with helium in drives and using microwave and heat-assisted magnetic recording to increase areal density and storage capacity. HDDs are expected to remain a popular choice for storage in the familiar 3.5 inch form factor for many years to come.
Solid state drives (SSDs) can be made smaller and use less power than hard disk drives (HDDs), do not make noise, and are more reliable due to the lack of mechanical parts. Many SSD manufacturers produce SSDs that can be used as drop-in replacements for 2.5 inch and 3.5 inch HDDs. The SATA interface and power connectors are the same as those on an HDD.
The memory stick form factor, once limited to 128 MB, now comes in versions as large as 2 TB and is used in mobile devices such as phones and drones. Intel’s 32 TB SSD, the DC P4500, is currently the world’s densest SSD and is designed for data center applications.
Solid state drives (SSDs) do not have moving parts, so they are less likely to fail due to mechanical issues compared to hard disk drives (HDDs).
However, SSDs do have a finite number of times they can be written to and read from before they stop working, and they are subject to wear and tear.
While most users never think about the lifespan of their SSDs, it is important to keep in mind that they are not immune to the laws of entropy and SSDs can fail over time.
| Pros | Cons | |
|---|---|---|
| HDDs | Budget-friendly. Lots of storage space. Standardized sizes make repairs and replacement easier. Amount of data written is not limited. Ideal for long term offline storage. – Storage for data which is not changing frequently. | Use a lot of power. Noisy. Moving parts make them prone to wearing out over time. Slover than SSDs. |
| SSDs | Faster than HDDs. Don’t generate noise. Use less power than HDDs. Wide range of form factors. No moving parts make them more durable than HDDs. | Less storage capacity than HDDs. Can be expensive. Difficult to recover data if it fails. Amount of data written is limited. Requires power to periodically refresh stored data. Ideal for system drive where performance is important. |
Most Frequent Questions
How Expensive Is SSD vs. HDD?
Comparing the price of a 1 TB internal hard drive and a 1 TB internal solid state drive, the hard drive is typically more affordable, with an average cost of about $60, while the solid state drive tends to be more expensive, at an average of around $150.
How Fast Is SSD vs. HDD?
While traditional HDDs typically have a data transfer rate of 30 to 150 MB/s, SSDs can transfer data at speeds of 500 MB/s or higher. For example, a standard SSD can copy a 20 GB file in less than 10 seconds, while an HDD would take at least two minutes to complete the same task. Some newer NVME SSDs can even reach data transfer speeds of up to 3,000 to 3,500 MB/s.
Hard drive or SSD for photos?
SSDs tend to fail more catastrophically than hard drives, and there is a lower chance of recovering lost images. However, they have lower replacement rates than hard drives. Age, rather than usage, is a significant factor in the failure of SSDs. They are also more expensive than HDDs.
HDD or SSD for media server?
An SSD server may have a faster read/write time and lower latency. However, it will also be more expensive for the same amount of storage. SSDs may not be the best choice for servers where unpowered states are expected for long periods of time.
Does an SSD really make a difference?
The faster data transfer speed of SSDs can significantly reduce waiting times for tasks such as launching games or programs. In the long term, this can lead to significant time savings. SSDs also tend to have faster load times for games compared to HDDs.
What should you put on SSD vs HDD?
For optimal performance, it is recommended to store your operating system and frequently used programs on an SSD. Large media files, infrequently accessed files, and productivity documents can be stored on a mechanical hard drive.
Is SATA HDD or SSD?
SATA hard drives are either HDDs or SSDs. While they both serve the same purpose, they use different technology to store data.
What is better for gaming HDD or SSD?
Solid state drives (SSDs) are faster at loading games and transferring data than hard disk drives (HDDs), but they are more expensive per gigabyte. When considering an SSD, it is important to consider the read/write speeds in order to gauge its performance. For gaming, a PCIe NVMe M.2 SSD is a MUST. It offers 5-10x speed of the SATA III SSD, making it perfect for games that rely heavily on storage access speed.
Is SSD better than HDD for long-term storage?
The answer depends on the usage. For long-term storage with infrequent access and/or unpowered times, an HDD may be better. For long-term storage with frequent access and constant power, an SSD may have a longer lifespan.
What are the signs my hard drive is failing?
Hard drives, both HDD and SSD, can fail without giving any warning. However, many people receive some warnings before a drive fails completely. Check out our guide on the signs of hard drive failure for more information.
Summary
SSDs are definitely being adopted more and are seen as the future of data storage. However, innovations for HDDs are still happening, making them a viable storage option for years.
Here is one thing everyone should do:
Everyone should check the health of their internal and external storage devices. All drive technology fails at some point. The only way to prevent data loss is to prepare for failure of your hard drive. To do this, use Hard Disk Sentinel to quickly assess the health of your hard drive. Then, you can deploy Hard Disk Sentinel as a tool for monitoring, maintaining, and backing up your data. This is the only reliable way to prevent data loss over time.
Choose SSDs for performance and HDDs for price. But you can have both! Use an SSD for quick access to files you are using often and an HDD for files, such as photos or archives, that you want to keep safe for a long time, even if the drive is unpowered. And, of course, use Hard Disk Sentinel to monitor both of them.
