【 Weak current College 】 solid-state disk SSD performance advantages of interpretation

The traditional hard disk is mainly composed of one or several round belt magnetic disc and several heads. Platters spinning at speeds of up to every minute 15000. Head read platter of magnetic signal. The traditional hard disk has two motors, disc rotation need disc motor driven head movement need to seek motor driven. In a random access to data, the hard drive first driven head moves to the data on the same track, and then wait for the disk to rotate to the track data sent to the head position. This mechanical structure resulted in a traditional hard drive there are two drawbacks, namely energy high and low reading and writing performance. If you have a hard drive, you can present mechanical hard drive handle more read and write requests, and consume less power and that the more the better. Solid-state disk SSD performance advantage can be a good solution to this problem.

Solid-state disk SSD performance to eliminate mechanical movement to reduce power consumption

Traditional hard disk is driven by motors rotating platters do, then head to read disc on magnetic signals. Motor needs to be a lot of power. Server-level hard disk speed can reach every minute 15000. FC hard drive in the work of State power can reach 17W ~ 20W, standby power is also more than 12W. And the SSD internal just chip, power consumption is smaller. Currently, the typical SSD work State power was 2W, standby power consumption is less than 0.1W.

A disk array will often have dozens or even hundreds of hard drives in operation, if the use of SSD, saving electricity very substantial. To equip 100 block FC hard disk arrays, for example, its power range 3000W ~ 3500W, adopting SSD hard drive, not only after their power consumption to reduce 1500W, array conversion for fans, power supplies, and other losses will decrease, the overall power consumption and eventually makes at least drop 2000W.

Solid-state disk SSD performance reduce sudden power reduction of power consumption

Only when the disc rotation speed reaches a specific value, the traditional hard disk to work correctly. If the standby of traditional hard drive you want to switch to a working state, it must be hard drive motor speed, maximum input current will achieve the functional State of 3 times, and duration longer, about 30 seconds. In other words, the hard disk will need to wait 30 seconds to make a good read and write operations.

In addition, when the head need to move to the disc at the specified range of reading and writing data, the head arms also need to be moved, this time while an action is very short, only a few milliseconds, but you need the current is very large, usually the hard disk Typ current of more than two times. Especially in the composition of the raid group disk array, a host of reading and writing will trigger a raid group multiple hard drives at the same time, move the magnetic head arm, accumulated together current is very large. If the system is not good, this large current can cause power supply output voltage drop, thereby causing the system to reset. To resolve this problem, increase the power of design capacity, therefore additional overhead, it will consume additional materials.

Solid-state disk SSD performance no sudden large current, starting current and operating current of basically the same. Therefore, use SSD array, power do not need to make additional power design, but also can reduce material consumption. Solid-state disk SSD performance from standby switch to working state the desired time is very short and can be more frequently will switch to standby SSD, thereby using less energy.

Solid-state disk SSD performance read and write performance improve dozens of times

Hard disk in a random read/write is necessary to move the magnetic head constantly to remove, cause inefficiencies. Now the fastest average mechanical hard disk head is moving time, that is to say 5ms 1 seconds heads move up to 200 times, i.e. a maximum processing 200 random read/write requests.

SSD without Magnetic heads, eliminates the mechanical operation of the time. SSD have to do is calculate the data stored in which Flash chip which location, and then on the location for read and write. Currently, the typical SSD per second maximum 16000 random read write, is the traditional hard disk of 80 times. Generally speaking, in highly random read-write using environment, 1 SSD can when 30 traditional hard disk drive to use. Web servers, database servers and file servers on random read/write performance is high, the SSD can better meet the needs of the application.

Solid-state disk SSD performance and mechanical hard drive combination

SSD have any disadvantages? mainly price problem. Since the Flash chip prices high, causing the SSD prices is the traditional hard disk several times or even dozens of times. At present, the SSD is mainly used in small-capacity, high demand for random read/write.

SSD performance, low energy consumption, but the price is quite high. Mechanical hard drive while the low-power high-performance, high capacity, however, the price is very cheap. Users can use a combination of both, high performance and low cost. For example, for database applications, and generally can be divided into table indexes and data areas tables index area the high frequency of access, and data area is relatively low. The user can put the table index zoning to SSD, data area to the mechanical hard drive, enabling better price/performance and energy efficiency ratio.