Introduction
A solid state disk (SSD) useing a solid state electronic memory chip array, is composed of a control unit and a storage unit (FLASH chip, DRAM chip). The specifications and definitions, functions, and usage methods of the SSD are exactly the same as those of the ordinary hard disk. The shape and size of the SSD are also identical to those of the ordinary hard disk. It is widely used in military, vehicle, industrial control, video surveillance, network monitoring, network terminals, power, medical, aviation, navigation equipment and many other fields. A hard disk drive (HDD), hard disk, hard drive, or fixed disk is an electro-mechanical data storage device that uses magnetic storage to store and retrieve digital data. Choosing a SSD or a HDD? It is necessary to know the differences between them. The following is a comparison between SSD and HDD for you.
SSD vs HDD
Catalog
Ⅰ What is a SSD?
1.1 Solid State Drive Definition
An SSD is a type of non-volatile storage media that stores persistent data on solid-state flash. From high-end game PCs to entry-level laptops, solid-state drives are becoming more and more common.
1.2 SSD Types
The storage medium of solid-state hard disk is divided into two kinds: one is to use flash memory as the storage medium, and the other is to use DRAM as the storage medium. The latest is Intel's XPoint technology.
- FLASH
Flash-based solid-state drives (IDEFLASH DISK, Serial ATA Flash Disk) use FLASH chips as storage media. It can be made into a variety of shapes, such as notebook hard drives, micro hard drives, memory cards, U disks and others. The biggest advantage of this SSD is that it can be moved, and the data protection is not controlled by the power supply. It can be adapted to various environments, and is suitable for individual users. It has a longer life span and varies according to different flash media. SLC flash memory generally reaches tens of thousands of times of PE, MLC can reach more than 3000 times, and TLC has reached about 1000 times. The latest QLC can also ensure a lifespan of 300 times. Even the cheapest QLC flash memory, can provide 6 years of write life. High reliability, high-quality household SSD have only one tenth of the failure rate of traditional household HDD.
- DRAM
SSD based on volatile memory such as DRAM is characterized by very fast data access. DRAM is used as a storage medium, and the application range of DRAM-based SSD is narrow. It imitates the design of a traditional hard disk, which can be set and managed by most of the file system tools of the operating system, and provides industry-standard PCI and FC interfaces for connecting to a host or server. Application methods can be divided into two types: SSD hard disk and SSD hard disk array. It is a high-performance memory that can theoretically be written infinitely. The only drawback is that it requires an independent power supply to prevent data loss. In fact, DRAM-based SSDs are relatively non-mainstream devices.
- 3D XPoint
Intel and Micron announced 3D XPoint as a new non-volatile memory technology in 2015. In principle, it is close to DRAM, but it is non-volatile storage. The read latency is extremely low, which can easily reach one percent of the existing SSDs speed. The disadvantage is that the density is relatively low compared to NAND flash. Its cost is extremely high, and it is mostly used in high-level desktops and data centers.
Ⅱ SSD Development Prospect
The solid-state drive market analysis report released by the American Grand View Research Company in February 2018 predicts that the global SSD market will reach US$25.51 billion by 2025. The widespread use of social media, the popularity of online commerce and the surge in media content will all promote the vigorous development of the SSD market.
Due to the popularity of smart phones and tablet computers, it is expected that the average storage capacity of households will increase sharply in the next few years. Consumers will continue to generate large amounts of digital content and data, and the demand for storage will continue to grow. In data centers, SSDs are more efficient than traditional hard drives. With the advancement of SSDs in performance and reliability, coupled with the continuous growth of storage infrastructure requirements, enterprises are increasingly inclined to adopt solid state drives. Therefore, the effect of saving cost and saving energy consumption is achieved.
It is expected that the average home storage capacity will be higher than that due to the popularity of smartphones and tablets, which enables consumers to generate large amounts of digital data and content. This has led to an ever-increasing demand for sufficient capacity to store content. The South American and MEA markets are mainly affected by the increase in the usage of laptops and smartphones embedded in SSDs. It is expected that increasing knowledge of the advantages of SSD over HDD will drive the demand for SSD in these regions during the forecast period. On the other hand, the high price of SSDs is expected to have a negative impact on demand.
The major players in the market include Intel Corporation, Micron Technology Corporation, Samsung Electronics, Seagate Technology and Western Digital Corporation. North America is temporarily in a leading position in terms of market revenue. Manufacturers are paying attention to the differentiation and innovation of SSD products to increase product coverage and revenue, while promoting market demand for SSDs.
Ⅲ SSD vs HDD
3.1 Interface Form
There are more common SSD forms, including SATA (commonly 2.5 inches), M.2, PCIe, NVMe, etc. The common ones are 2.5-inch SATA and M.2. And M.2 has multiple length versions: 2242, 2260 and 2280 (common in notebooks). In general, the form of hard disks are distinguished by interfaces. There is only one common HDD form, SATA, which is available in 2.5-inch and 3.5-inch versions. The difference between the two is the size. 2.5-inche appears in notebooks, and both forms can appear in desktops.
3.2 Comparison Between SSD and HDD
What is the difference between SSD and HDD? In fact, solid-state drives and hard disk drives have their own advantages and disadvantages. The following we will give you a thorough understanding through a comprehensive comparison.
|
Item |
Solid State Drive (SSD) |
Hard Disk Drive (HDD) |
|
Capacitor (Max) |
4 TB |
10 TB |
|
Cost |
Expensive |
Cheap |
|
Random Access |
Fast |
Low |
|
Writing Times |
Based on capacitor |
Unlimited |
|
Power Efficiency |
High |
Low |
|
Noise |
* |
Always |
|
Operating Temperature |
Low |
High |
|
Speed |
Fast |
Low |
|
Anti-vibration Capability |
Sound |
Poor |
|
Data Recovery |
Hard |
Easy |
|
Service Durability |
Durable |
Weak |
3.3 SSD Explained
Compared with traditional hard disk drives, solid-state hard drives have obvious advantages in terms of data reading speed, shock resistance, power consumption, operating sound, and heat generation:
1) Reading Speed
The reading speed of solid-state hard drives can generally reach 400M/s, and the writing speed can also reach 130M/s or more. Under normal circumstances, the maximum continuous read and write speed of HDD is about 200MB/s, but ordinary SATA SSD can easily achieve a speed of 500MB/s, while the maximum read of NVMe SSD can exceed 3000MB/s. Compared with HDD or even eMMC, SSD operational speed is incredible, which is very useful for transferring large blocks of data.
|
Interface |
Agreement |
Speed (Max) |
|
SATA |
AHCI |
600 MB/S |
|
M.2 |
AHCI |
600 MB/S |
|
NVMe |
3200 MB/S |
|
|
U.2 |
NVMe |
3200 MB/S |
|
PCIe |
NVMe |
3200 MB/S |
2) Anti-vibration Capability
Traditional HDD has high-speed rotating magnetic read head inside, which have poor shock resistance. Therefore, if it is used in motion or vibration, it is easy to damage the hard disk. While there is no damage to the moving parts of the SSD, and no damage to the drive motor. This reliability makes SSD suitable for portable external drives.
3) Power Consumption
Solid-state hard drives have low power consumption, especially device on standby, while HDDs do not.
4) Noise
Basically, no noise can be heard during the operation of the solid state drive, while the mechanical hard drive can generally hear the internal disk rotation and vibration when listening closely. The noise of some mechanical hard drives that have been used for a long time is more obvious. The main reason for the noise is the different structure of the two. Although both SSD and HDD can store content, their structure is completely different. There are mechanical structures such as motors, discs, and magnetic heads inside the HDD. The disc rotates during operation, so there will be slight vibrations and sound when the HDD is working.
The internal structure of SSD is more like a U disk, with a master control, flash memory chips, etc. Since there is no mechanical structure such as rotating or moving part when working, no vibration or sound when the SSD is working. Since the HDD needs to rotate the disc during operation, the shock resistance and performance are relatively weak. And the power consumption is higher during standby rotation (except for stalls). SSD has no mechanical structure to rotate, so it has strong shock resistance, better performance, and low power consumption.
5) Portability
SSDs are smaller and lighter than HDDs. This development makes it possible to create today's ultra-thin laptops, tablets and other mobile devices. The thinnest SSDs are only a few millimeters wide and only a few inches long, making them ideal for the smallest high-speed devices.
6) Heating
The SSD generates less heat, and even after a period of operation, no obvious heating is felt on its surface. But HDDs can obviously felt hot when touched by hand.
3.4 SSD Shortcomings
Solid-state hard drives have shortcomings in terms of capacity, price, number of writes, and data recovery. Let us introduce them in details below:
1) Capacity
At present, the capacity of solid-state hard drives is generally between 64GB~4TB. The traditional ordinary hard disk drives are now basically between 500GB~10TB, and the mainstream is 1TB and 2TB. For example, the capacity of a 2.5-inch HDD can be up to 4TB. Even an OLC SSD, the current mainstream capacity is still concentrated at 256GB and 512GB. Although large-capacity can be made, medium-capacity SSDs are easier to accept due to price.
2) Cost
Although the price of SSD is gradually decreasing and its advantages are obvious, the current price is still significantly higher than that of HDDs. At present, The price of a 1TB internal 2.5-inch hard drive is between $40 and $60, but at the time of writing, the cheapest solid-state drive with the same capacity and form factor starts at about $125. Hard drives translate to 4 to 6 cents per gigabyte, while solid state drives cost 13 cents per gigabyte. In terms of price, HDDs are much cheaper. In addition, the advantage of HDDs is that they are a mature product, and for the same amount of storage, their prices are usually cheaper than solid-state drives.
3) Reading Times
SSD has a limit on the number of writes, which means that there is a life problem. The SLC SSD has 100,000 writes, while the MLC SSD used has only 10,000 writes. Theoretically, the life of the SSD will be shorter, but actual tests can find that the daily use of the MLC1 SSD can also be used for about five years, so the lifespan is also acceptable. Although the mechanical hard disk has no limit on the number of writes, the basic use is three to five years. So there is actually not much difference between the two.
4) Data Recovery
After the data on the solid state drive is deleted, it cannot be restored by other software, while the traditional hard disk drive can be retrieved through some professional data recovery software, which is also a deficiency of the solid state drive.
SSDs are faster, lighter, more durable, and consume less energy. HDD has advantages in capacity and price. The selection should be based on actual needs.
0 comment