Hard disks hare divided into three types: solid-state hard drives, mechanical hard drives, and hybrid hard drives. The vast majority of users use solid-state hard drives and mechanical hard drives solutions. The hybrid hard disk market share right now is tiny.
- Hard Disk Drive (HDD)
It is a traditional hard drive before there was no solid-state hard drive. The structure of the hard disk drive is mainly composed of one or more aluminum or magnetic-glass discs, magnetic heads, controllers, etc. When the hard disk is working, the magnetic head is suspended on a magnetic disk rotating at high speed to read and write data.
The advantages are large capacity, low price, mature technology, data recovery can be done when the hard disk is damaged. Still, the disadvantages are mainly slower speed than the solid-state hard disk, high heat, high noise, and weak shock resistance.
- Solid State Drive (SSD)
Solid State Drive is a new type of hard drive introduced after the hard disk drive, and it is also one of the preferred hard drives for installation. They are all set as master drives and significantly increase the speed of the system. The solid-state hard disk is an array of storage composed of a plurality of flash memory chips plus the central control and a cache.
The advantages are faster-reading speed, and smaller seek time than a hard disk drive, which can improve the reading and writing speed of systems, software, games, etc. It is quiet, shock-proof, drop-resistant, low power consumption, lightweight, and low heat generation. The disadvantages are the high price and small capacity. When ample storage is needed, it often needs to be used with a mechanical hard disk.
- Solid State Hybrid Drive(SSHD)
SSHD is equivalent to the combination of hard disk drives and solid-state drives. They use smaller capacity flash memory particles to store mostly used files, like os software. While magnetic disks are the essential storage medium. Flash memory only serves as a buffer and will be more commonly used. Saving files to flash memory reduces seeking time, thereby improving efficiency.
The advantages and disadvantages of SSHD are that the read and write speeds are faster than mechanical hard drives, but they are not as quickly as solid-state hard drives. Like mechanical hard drives, they have significant heat generation, considerable noise, and vibration.
What is NAS hard drive? If you want to add a hard drive to your NAS, what model should you choose?Compared with desktop hard drives, NAS hard drive is suitable for 7×24 power-on operation without interruption. At a speed of 5400rpm, both reading and writing are entirely silent and high-performance data throughput, keeping it quiet at night and not affecting sleep.
The leading critical technologies of NAS include:
- Time-Limited Error Recovery
- When the NAS hard drive can’t read a data block, it will try to read it for 3-5 seconds (You can set this time limit in the firmware). if it still can’t read any data, it will immediately mark this block as bad sectors, and report to the control unit, then read data from other redundant disks to reconstruct this small part of array data. TLER significantly reduces the drop rate of the RAID array, improves reliability and stability.
- Perpendicular Magnetic Recording
Commonly known as the 10th generation hard drive technology, hard drive manufacturer Seagate first invented it. The perpendicular recording technology (PMR) can make the magnetic recording density reach 625GB / in², which doubles the current magnetic recording density.
PMR recording technology is to change the arrangement of the magnetic disk for longitudinal recording, from the original surface parallel to the surface perpendicular, thus increase the data access bit density.
- Helium-filled package
The helium-filled hard disk is to replace the air used for hard drive filling with helium. Because the density of helium is very low, and it can create a stable environment more than air.
Helium hard disks have two main advantages.
- First, helium-filled hard drives can be made thinner and have the same thickness. Traditional hard disks can now hold five disks, but helium-filled hard disks are now the first One generation, but already able to hold seven drives. The upgrade of 5 discs to 7 discs makes the capacity of the helium hard disk can be 6TB.
- It is also conducive to reducing the power consumption of the hard disk. This advantage is mainly due to the low density of helium. Due to the low density, the resistance of the hard disk during rotation will be much smaller.