Solid State Drives (SSDs) are made using solid-state electronic storage chips. They consist of a control unit and storage units, including FLASH chips and DRAM chips. SSDs have the same interface standards, definitions, functions, and usage ways as traditional hard drives. They also have the same appearance and size as regular hard drives. SSDs are widely used in fields like the military, automotive, and industrial control sectors. They are also common in video surveillance, network monitoring, power, healthcare, aviation, and navigation equipment.
The temperature range for their chips is quite wide. Commercial-grade products work between 0-70°C. Industrial-grade products can run from -40 to 85°C. Although they are more expensive, SSDs are gradually becoming popular in the DIY market. Since SSD technology is different from traditional hard drive technology, many new storage companies have emerged. Manufacturers only need to buy NAND storage and pair it with the right control chip to make an SSD. The latest generation of SSDs commonly use interfaces like SATA-2, SATA-3, SAS, mSATA, PCI-E, NGFF, CFast, and SFF-8639.
Solid State Disk (SSD)
Application Areas: Military, Automotive, Industrial Control, Power, Medical, etc.
Composition: Composed of a control unit and a storage unit.
Classification:
There are two types of storage media used in solid-state drives. One type uses flash memory (FLASH chips) as the storage medium. The other type uses DRAM as the storage medium.
Flash-based SSDs:
Flash-based solid-state drives (IDEFLASH DISK, Serial ATA Flash Disk) use FLASH chips as the storage medium. These are commonly referred to as SSDs. The appearance of such SSDs can vary. They can be designed as laptop hard drives, micro-drives, memory cards, or USB flash drives. The biggest advantage of this type of SSD is its portability. It provides data protection independent of power control. It can adapt to various environments, making it suitable for personal users. Generally, the number of erase cycles for these SSDs is around 3000 times. For example, if you use a commonly used 64GB SSD, the SSD’s wear-leveling mechanism determines the total writable data. The writable data is 64GB times 3000 cycles. This equals 192,000GB. If you are an avid video downloader who deletes 100GB of data daily, you can use it for 1,920 days. This is calculated by dividing 192,000 by 100. This usage period equals approximately 5.25 years. If you’re an average user writing less than 10GB per day, you can use it continuously for 52.5 years. If you’re using a 128GB SSD, it will last for 104 years without interruption! This is the same concept as conventional HDDs in that, theoretically, it can be read and written infinitely.
Cloud Storage SSD
DRAM-based SSDs:
DRAM-based solid-state drives use DRAM as the storage medium and have a narrower range of applications. They emulate the design of traditional hard drives. Users can manage and set them up using file system tools from most operating systems. DRAM-based SSDs offer industry-standard PCI and FC interfaces for connecting to hosts or servers. These drives can be used as SSDs or SSD arrays. DRAM SSDs offer high performance and long lifespan but need an independent power source to protect data security. Still, DRAM SSDs are considered non-mainstream devices.
Development History
In 1956, IBM invented the world’s first hard disk.
Intel Solid State Drive
In 1968, IBM reintroduced the feasibility of “Winchester” technology, laying the foundation for the direction of hard disk development.
In 1970, StorageTek (now Sun StorageTek) developed the first solid-state disk drive.
In 1989, the world’s first solid-state disk appeared.
In March 2006, Samsung became the first company to release a 32GB solid-state drive for laptops.
In January 2007, SanDisk released a 1.8-inch 32GB solid-state disk product, followed by a 2.5-inch 32GB model in March.
In June 2007, Toshiba launched its first 120GB solid-state drive for laptops.
In September 2008, MemoRight SSD was officially released. It is a product from China-based Yizheng. This marked China’s accelerated entry into the solid-state drive industry.
In 2009, SSDs experienced explosive growth. Major manufacturers entered the market. This marked the official entry of storage virtualization into a new phase.
In February 2010, Micron released the world’s first SATA 6Gbps solid-state drive. This release broke the 300MB/s read and write speed limit of SATAII interfaces.
At the end of 2010, Renice introduced the world’s first high-performance mSATA solid-state drive and obtained a patent.
In 2012, Apple used a 512GB solid-state drive in its laptops.
On August 1, 2015, TekCore launched the first Type-C interface mobile solid-state drive. It features the latest Type-C interface. This supports USB dual-side insertion.
On January 1, 2016, Chinese storage manufacturer TekCore released the world’s first Type-C fingerprint-encrypted SSD.
Basic Structure
Flash-based SSDs are the main type of solid-state drives. Their internal structure is very simple. The main part of the SSD is a PCB (printed circuit board). On this PCB, the key components are the control chip and the cache chip. Some low-end SSDs do not have a cache chip. The flash memory chips are used to store data.
Common SSDs on the market use control chips from companies like LSISandForce, Indilinx, JMicron, Marvell, Phison, Goldendisk, Samsung, and Intel. The control chip is the “brain” of the SSD. Its job is to manage how data is distributed across the flash chips. It also transfers data between the flash chips and the external SATA interface. The capabilities of different control chips can vary greatly. These differences affect data processing speed, algorithms, and how the chip reads and writes data. As a result, SSDs with different control chips can have performance differences of up to several times.
Main Control Chip and Cache Chip
Next to the main control chip is the cache chip. Like traditional hard drives, solid-state drives (SSDs) need high-speed cache chips. These chips help the main control chip in data processing. It’s worth noting that some low-cost SSD solutions skip the cache chip. This decision saves on costs but can affect performance during use.
Flash Memory Chips
Most of the remaining space on the PCB board is used by NAND Flash memory chips. These chips are placed beside the main control chip and the cache chip. These NAND Flash chips are divided into SLC (Single-Level Cell), MLC (Multi-Level Cell), and TLC (Triple-Level Cell) NAND Flash.
Comparison with Traditional Hard Drives
The interface standards of solid-state drives (SSDs) are almost the same as those of traditional hard drives. Their definitions, functions, and usage ways are also similar. Their size and shape are also very much like the common 2.5-inch hard drives.
SSDs offer several advantages over traditional mechanical hard drives. They have faster read/write speeds. SSDs are lighter in weight. They consume less power and have a smaller size. However, there are also some disadvantages. Although IDC considers SSDs to be mainstream in the storage market, they are still relatively expensive. They have lower capacity. Recovering data from them is harder when they are damaged. Some people also believe that SSDs have a shorter lifespan compared to traditional hard drives.
The main factors affecting SSD performance include the control chip, NAND flash memory, and firmware. Even with the same other conditions, the type of interface used can also affect SSD performance.
The most common interfaces are SATA (with 3Gb/s and 6Gb/s speeds), and there are also SSDs with PCIe 3.0 interfaces.
Because SSDs use a different design and data-reading principle than traditional hard drives, their internal structure is also quite different. In general, SSDs have a simple design. They can often be disassembled. Many performance reviews of SSDs include internal photos.
On the other hand, traditional mechanical hard drives read and write data by using spinning disks. These disks generate airflow to lift the read/write head. The head then moves to different tracks. The structure of mechanical hard drives is more complex and precise, and they are usually not meant to be disassembled. Opening them cause damage, making the drive unusable. This is why we rarely see disassembly photos in mechanical hard drive reviews.
Advantages
- Fast Read/Write Speeds: SSDs use flash memory, which allows for faster reading and writing compared to mechanical hard drives. Since SSDs don’t use a read/write head, seek time is almost zero. The continuous write speed of SSDs can be very fast, with many manufacturers claiming speeds over 500MB/s. The real advantage of SSDs is in random read/write speeds, which directly impact most everyday tasks. SSDs also have much lower access times. For example, a typical 7200 RPM mechanical hard drive has a seek time of 12-14 milliseconds. An SSD can reach 0.1 milliseconds or even lower.
- Shock Resistance: Traditional hard drives are disk-based, with data stored on magnetic platters. In contrast, SSDs use flash memory chips. These are like those in MP3 players or USB drives. Thus, they don’t have any moving parts. This makes SSDs more resistant to damage from movement, drops, or shock. Compared to traditional hard drives, SSDs have a significant advantage in durability.
- Low Power Consumption: SSDs consume less power than traditional hard drives.
- No Noise: SSDs don’t have motors or fans, so they run with zero noise. Flash-based SSDs consume less power and produce less heat during operation, though high-end or large-capacity models consume more power. SSDs have no moving mechanical parts. Thus, they are less prone to mechanical failures. They are more resistant to shock, vibration, and impact. They also generate less heat and dissipate heat more quickly.
- Wide Operating Temperature Range: Typical hard drives only work within a temperature range of 5-55°C. Many SSDs can operate from -10 to 70°C. SSDs are smaller and lighter than traditional hard drives of the same capacity. The chips in SSDs can operate in a broad temperature range (-40 to 85°C).
- Lightweight: SSDs are lighter than traditional 1.8-inch hard drives, typically by 20-30 grams.
Disadvantages
- Capacity: The greatest capacity of SSDs is now limited to 4TB. For example, SanDisk’s Optimus MAX (Titan) offers this capacity.
- Limited Lifespan: Flash memory in SSDs has a fixed number of write cycles. This is one reason many people complain about the short lifespan of SSDs. One full write cycle (an erase-write operation) is called one P/E cycle. The lifespan of flash memory is measured in P/E cycles. For example, a 34nm flash chip last for 5000 P/E cycles. In contrast, a 25nm chip only last for 3000 P/E cycles. With improvements in SSD firmware algorithms, new SSDs can reduce unnecessary writes, improving their lifespan. For instance, a 120GB SSD will count one P/E cycle only after writing 120GB of data. Even if you write 50GB per day, you would finish one P/E cycle every two days. Writing 3000 P/E cycles would last about 20 years. By that time, SSDs would be replaced with more advanced technology. In practice, users carry out more random writes. They do this more than continuous writes. This can cause more wear. It can also lead to bad sectors over time. Each sector in an SSD can be rewritten up to 100,000 times (SLC). Still, some applications (like operating system log files) repeatedly read and write to the same sectors. This can shorten the SSD’s life. But, wear-leveling algorithms help manage storage cells, extending the SSD’s lifespan. SLC memory has a write lifespan of 100,000 cycles. MLC memory lasts about 10,000 cycles. Cheaper TLC flash has only 500-1000 cycles.
Proper Use and Maintenance
The most important rule for using and maintaining a solid-state drive (SSD) is that older habits do not apply. These habits were formed in the mechanical hard drive era. This is particularly true for SSDs.
- Do not use defragmentation
Defragmentation effectively speeds up mechanical hard drives. But, it is harmful to SSDs. SSDs have a finite number of write cycles, and defragmenting will wear out the drive much faster. SSDs already have an effective garbage collection mechanism. It acts as disk defragmentation, so there is no need to do it manually. Windows’ defragmentation tool was designed for mechanical drives and does not help SSDs.
Also, it is recommended to turn off Windows 7’s Superfetch and Windows Search functions. These features don’t provide much advantage, and disabling them can reduce the read/write frequency on the SSD. - Use small and few partitions
This is related to the SSD’s garbage collection mechanism. When deleting files, SSDs wipe the entire area where the invalid data is stored. The process involves collecting valid data, moving it to free space, and then clearing the “problem area.”
This means that you should not fill up the SSD’s capacity when partitioning. For example, a 128GB SSD is usually marketed as 120GB, with some space reserved. By partitioning only 100GB, leaving more free space, the SSD’s performance will improve. This free space is used for internal improvement, like wear leveling, garbage collection, and bad block mapping. This practice is called “small partitioning.”
“Few partitions” refers to another concept, focusing on the importance of “4K alignment” for SSDs. If you have too many partitions, space will be wasted. Additionally, too many partitions may cause misalignment. This misalignment can affect performance. For 4K alignment, use Windows 7’s built-in partition tool. It guarantees the partitions are 4K aligned. - Leave enough free space
The more data you store on an SSD, the slower its performance becomes. If a partition is used beyond 90% of its capacity for too long, the SSD is more to fail.
Hence, regularly clean up unnecessary files. Set an appropriate virtual memory size. Store large files like movies and music on mechanical hard drives. Make sure the SSD partition has enough free space. - Update firmware regularly
The firmware is like the BIOS of the motherboard, controlling all internal operations of the SSD. It directly affects the SSD’s performance, stability, and lifespan. Good firmware uses smart algorithms to reduce unnecessary writes. This helps lessen wear on the flash memory and increases the SSD’s lifespan.. Hence, updating the firmware to the latest version is essential. It not only improves performance and stability but also fixes bugs. - Learn to use the TRIM command
The TRIM command can restore the SSD’s performance to factory levels. But, it is not recommended to use it too often. Each TRIM reset is like completing a full write cycle. This can impact the drive’s lifespan.
With the rapid development of the internet, the demand for data storage continues to rise. Many storage companies now offer portable SSDs, including those with Type-C interfaces and fingerprint recognition features.