Differences between SSD and HDD disks

A storage drive is an indispensable component of a computer that performs many functions, from operating system operation to information storage and processing.
The first type of drive is HDD (Hard Disk Drive, hard disk), which works on magnetic technology. The second type is SSD (Solid State Drive), on solid-state technology. The third type of disk is hybrid, known as SSHD (Solid State Hybrid Drive). Each of these types has its own features and is suitable for different tasks. SSHD is hardly ever used.
 

How server drives differ from standard drives

Servers run continuously, unlike regular PCs. This includes disks. They provide uninterrupted operation of the operating system, applications and data storage, simultaneously processing requests from multiple users. They are characterized by increased fault tolerance, excellent response, high resource capacity, and can automatically correct errors.
 

What is HDD

It is a data storage device based on magnetic recording. It is used everywhere, widely used in computers, video systems. Information is recorded on plates made of ceramic or glass, covered with a magnetic layer, which rotate. Read data from the disk head, which does not contact directly with the plates. Due to the lack of mechanical contact, HDD is considered a reliable and durable data storage device.
 

Advantages of HDD

• Low price. A classic option for those who need to store data without significant costs.
• Large capacity, which avoids constant cleaning and transfer of files.
• Ability to recover - HDDs fail gradually, allowing the system to warn the user about the possible threat of data loss.
• No limitations on overwriting.

 

Disadvantages of HDD

HDD processes information slowly. The read/write speed depends on the spindle speed.
The position of the writing heads is adjusted so precisely that a minor physical impact can disable the drive, causing physical damage to the platters with the risk of data loss.
Noise. The sound is not loud, but the constant crackling annoys many users.
 

What characteristics are important for HDD

Form factor is the physical size. There are two popular formats, 2.5 and 3.5 inches. Smaller drives are typically used in laptops because they can fit into limited case space.
Capacity - determines how much data you can store in the memory. Capacities can range from 250 GB to several TB.
Spindle Speed - the more RPMs the spindle makes per minute, the faster the data can be accessed. However, high speeds require more cooling and can result in more noise.
 

SSD disk - what is the difference from HDD

SSD is an alternative to hard disk drive that is gaining popularity among users. It is organized in a completely different way and has more in common with a USB flash drive than with a HDD. The storage device uses an integrated circuit and memory to store data. SSD is more resistant to shocks and drops, works quietly, does not require cooling, is characterized by a short response time and less delay in reading and writing data.
Currently, most SSDs are equipped with NAND flash memory. For higher performance, some SSDs are built with RAM memory. These devices can use different power sources, such as rechargeable batteries, and retain data in the event of a power failure.
 

Pros of SSDs

Which is better - SSD or HDD? SSDs are faster, operate at lower temperatures and are better protected from physical impacts. They also provide stability and security of stored data, consume less power, are lightweight and operate without noise. And when you look at Enterprise-class SSDs, they are also more stable and durable than HDDs. The devices are available in a variety of sizes and form factors, making them convenient for different types of devices. SSDs are what makes servers run perfectly.
 

Disadvantages of SSD compared to HDD

High price. The cost of SSD significantly exceeds the price of HDD. This is due to the use of rare chemical elements in the production of chips with NAND-chips, as well as the complexity of production technology.
Small memory capacity. SSDs cannot offer the same capacity as HDDs, which can store up to 16 TB.
Difficulty of recovery. SSDs can fail, and data recovery is a complex process that requires knowledge and significant cost. This is due to the complex encryption mechanism and the need to capture information from multiple memory chips.
Chip wear. Unlike mechanical disks, the life of each flash memory chip is limited, and once it is exhausted, the drive becomes useless.
 

What characteristics are important for SSDs

Pay attention to the connector and interface, which determine the type of connection and affect speed. A connector is a port on the motherboard for an SSD die or cable. Interface is a set of technologies that facilitates communication between the motherboard and the drives.
 

SSD Interfaces

• SATA - most often represented as an L-shaped connector to which the SSD cable is connected, or in M.2 format. The speed is up to 600 MB/s, which is 5-6 times faster than HDD. The interface has different versions - SATA II and SATA III.
• NVMe - provides data transfer speeds from 1.5 to 7.5 GB/s, surpassing SATA by 13 times. These drives are often presented in M.2 format, but are also available in other variants. NVMe Versions: Gen 3, Gen 4, and Gen 5 (or PCIe 3.0, 4.0, 5.0) - each successive one is twice as fast as the previous one. Gen 3 and Gen 4 drives are the most common. Gen 5 is new and has not yet reached its full potential.

When you choose an SSD, pay attention to the connectors and slots on the motherboard:

• SATA slot - supports SATA SSDs and older HDDs. 2.5-inch disks are connected by a cable to the L-shaped connector and require a separate cable for power supply;
• M.2-slot with SATA interface - a compact version of SATA-SSD, which looks like a thin wafer with chips and does not require additional cables;
• M.2-slot with NVMe interface - looks similar to SATA M.2 but surpasses it in speed. It can be connected directly to the processor, which further speeds things up;
• U.2 slot - rarely found in ordinary computers, allows you to connect fast NVMe drives;
• PCIe slot - an equally rare way to connect to a computer. SSD is inserted into the universal slot on the motherboard where the graphics card is usually located. It can support multiple M.2 slots and combine them into RAID arrays.

If you are planning to use an M.2 drive, you should also consider the length of the drive. There are five types: 2230, 2242, 2260, 2280 and 22110, the first two digits are the width and the last digits are the length of the die.
When choosing an SSD, you should consider the type, connection standard, speed to find the most suitable one compatible with your motherboard.
 

SSD in servers

The use of SSDs in servers offers a number of advantages and is used in a variety of applications:

• High-load databases - 1C, SQL, CRM, ERP;
• Critical data - sensitive files, frequently used applications, operating systems;
• High-performance applications - examples are AR/VR, industrial automation and robotization systems where every millisecond counts;
• To create virtualized computing units of base stations in mobile networks;
• When performing in-memory computation operations with large amounts of information;
• Real-time data processing. This is especially important for tasks related to analytics, machine learning, and financial transactions;
• Online trading - allows minimizing reaction time to changes in the market.

SSD applications can be useful in other areas where speed and stability are considered key factors.
 

Differences between SSD and HDD, which disk is better, what is the difference

There are a few key differences between SSDs (solid state drives) and HDDs (hard disk drives). Let's look at the difference between SSDs and HDDs in simple terms.
 

How data is stored and transferred

SSD is a device with no moving parts, HDD is a mechanical storage medium where information is written to rotating magnetic disks using a head.
 

Energy-dependent, compact, reliable

SSDs are non-volatile because they are immobile. They are more compact and lightweight, making them ideal for laptops and devices with limited enclosures. SSDs are resistant to drops and other damage, and are more reliable when you consider the Enterprise class.
 

Speed and price

SSDs have high write and read speeds, making them ideal for fast data processing. However, SSDs are more expensive for the same storage capacity as HDDs.
SSDs have a limited number of write and erase cycles - over time they lose performance and reliability. HDDs are completely free of these disadvantages.
 

SSD or HDD - which drive is better?

If you need to process large amounts of data at high speeds, SSD is the ideal choice. HDD is the right solution if you need backup, archiving or large storage capacity.
Table 1 - SSD disk and HDD disk - usage comparison
Gaming PCs: SSDs are more popular because of their high read and write speeds. Gamers around the world recognize SSDs as the undisputed leaders.
Office and home PCs: If you don't need a big capacity of storage, you can use SSD in a performance computer for sound, photo, video, 3D graphics and game creation. Otherwise, HDD is the choice.
Laptops: SSDs are smaller, lighter and quieter, and power consumption is low. These are all very important for running on a laptop without a power connection. However, SSD has a limited number of write cycles. Therefore, for novice notebook users HDD will be preferable.
 

Do you need an HDD when you have an SSD

If you need to combine high system speed and spacious storage, you should pay attention to hybrid models working in tandem with HDD and SSD.
It should not be forgotten that the system performance also depends on the other components. A fast SSD cannot compensate for an inferior processor, lack of RAM or limited graphics performance. All computer components must be balanced and meet the requirements of applications.
 

Summary

Solid State Drives (SSDs) and Hard Disk Drives (HDDs) have similar physical characteristics, but the way they store data is different. HDDs use magnetic platters, while SSDs use flash memory. HDDs are cheaper with more physical memory, SSDs are faster and more power efficient. Therefore, you should base your choice between HDD and SSD on your needs.