Do you feel that solid-state drives are getting slower and slower? What is the matter with this? There are so many legends about solid-state drives on the rivers and lakes, which ones are true? To answer this question, we have to mention the erasing process (P/E) of solid-state drives.
For ease of understanding, we use these small grids to represent the unit storage space of the flash memory, where the white grids represent the empty storage space, and the blue grids represent the storage space with stored data. A storage area is represented by a gray area consisting of small grids. When you delete a file, the hard drive will not immediately erase the data in the corresponding location, but will mark it with a mark: "empty".
When you want to store a file, the hard disk will not write new data in the marked position but will store the data in the blank area to use more storage space. With the increase in the number of reads and writes, the blank areas in the hard disk are almost used up. If you want to write new data at this time, you need to vacate these marked positions, that is, the erase tape. marked data. But to erase data, not only the corresponding grid but a whole area must be cleared before new data can be written. This process is called write amplification (WAF), and it means more complex steps, longer time-consuming, and more erase and write cycles.
Let's take a concrete example:
When writing data "7", the worst case is that there is no clean grid in a block, but the invalid data (marked as "empty") can be erased, so all the data should be erased. Read the cache, erase all data in the area, and write new data into it. Then the write amplification brought by this operation is: originally only one grid needs to be written, but it actually causes the write operation of the entire block.
At the same time, the operation that originally only needed to write data in a simple step became:
The cache reads the entire area - the cache modifies the data erases and clears the entire area writes all the data, a total of four steps, and the delay will be greatly increased compared with direct writing. Knowledgeable friends all know that numbers such as 256 and 512 are "integers" in the computer field. Why are the solid-state drives on the market often 240G or 480G? This is by reserving space and forcibly preventing everyone from filling up the hard disk, thereby prolonging the use time of the hard disk.
Although overfilling the disk will affect the performance of the SSD, the real impact on life is the number of erasing and writing. When the number of erasing and writing reaches the limit, the SSD will be damaged and the data in it will be lost, so how to judge How long can a solid state drive "live"?
How to Calculate SSD Lifespan?
SSD life calculation is very simple, For example:
If you buy a 2TB solid-state hard drive, the total number of erasing and writing is 1000. Assuming that 100GB of large-capacity data is written to this solid-state hard drive every day, then according to the calculation, you can get:
Service life: (2048*1000)/(100*365)=56 years.
How to maintain the solid state drive? Are all the rumors true?
After reading this, you already know not to overfill the hard drive, but there is a lot of experience in solid-state drive maintenance circulating in the rivers and lakes! Are those true?
Partitioning affects SSD performance - FALSE!
Partitioning a solid-state drive does not affect the performance of the hard drive at all.
Some people may say, "The data is stored in the C drive, and the reading speed is the fastest", and "Every time a partition is divided, the system will reserve a certain amount of cache, resulting in a certain amount of capacity waste." "The number of erasing and writing is limited, and long-term Reading and writing the system C drive may shorten the lifespan." In fact, for solid-state drives, these worries are superfluous!
The main shaft of the mechanical hard disk rotates at a constant angular velocity so that the area of the disk sector swept by the outer ring is always larger than that near the inner ring. The C disk is located in the outer ring. The sector area swept by the magnetic head is the largest per unit of time, so When the system is loaded into the C drive, the speed of the D, E, and F drive decreases.
The solid-state drive is mainly composed of components such as the main control and flash memory particles, and there is no mechanical structure of a mechanical disk. No matter where the data resides in the solid state, the speed is the same.
And with the continuous development of solid-state drives, the current solid-state drives on the market are also constantly being upgraded, and they are becoming more and more mature in functions such as garbage collection, reserved OP space, automatic allocation, and erase-write balance. Don't worry about wasting capacity or over-erasing a location.
Therefore, the editor recommends that the solid-state hard disk be partitioned according to the needs. If the funds are limited and the solid-state hard disk below 256G is equipped, the editor recommends not to partition.
Disk defragmentation optimizes performance - FALSE!
In a mechanical hard disk, files are not continuously stored in contiguous clusters of the disk but exist wherever there is space. Since files are scattered and stored in different places on the entire disk, disk fragmentation occurs. In the process of saving the new and deleting the old, the disk fragments become scattered. In this case, reading increases the hard disk seeks time and also increases power consumption.
Therefore, the disk defragmentation function is to organize the fragmented files on the disk and integrate the fragmented files, which speeds up the seek time of the disk and thus speeds up the overall speed.
So why don't SSDs need defragmentation?
The seek time of solid-state drives is almost zero: the storage units of solid-state drives are electronic storage based on flash memory particles, so the seek time is theoretically eternal, and its performance mainly depends on the performance of the main control chip and the flash memory. Particle process.
Solid-state drives have a limit on the number of reads and write: disk defragmentation is equivalent to a full-disk read and write, which is equivalent to reducing the number of erasing and writing by 1. It can be seen how much disk defragmentation consumes the life of solid-state drives.
In fact, after the system recognizes that the SSD is installed, it will turn off this function by default. So let's not turn it on when using an SSD just because it looks like it can "save hard drive space".
To update SSD firmware - really!
If we compare a solid-state drive to a small computer, the firmware can be understood as its operating system. Firmware controls all the internal operations of the SSD, which can directly affect the performance, stability, and lifespan of the SSD. Excellent firmware can reduce unnecessary writes to the SSD, thereby extending the life of the SSD while improving its performance of the SSD. So we have to update the latest firmware officially released in time.
Turning on Trim can improve hard disk performance. - real!
The Trim command is also called disable delete notify. As we said before when a solid-state drive deletes a piece of data, it first marks the data, and when the system asks to write data in the marked place, it will erase the unused data. In fact, it is impossible to do the best at the most appropriate time. Optimization.
Trim can solve this problem very well. After Trim is turned on, the solid-state drive can immediately delete the content that needs to be deleted, avoiding the embarrassment of waiting until the data is to be written. Trim didn't change what it was going to do, it just did it ahead of time. So when everyone uses it, the speed goes up. Trim can effectively reduce write amplification, thereby achieving higher throughput and increasing the durability of solid-state drives. After Trim is turned on, it is basically impossible to restore the accidentally deleted data...
To sum up, the reason why SSDs are getting slower and slower is that the mechanism of SSDs is based on the principle of write amplification. So in order to ensure that the solid-state drive can always run at high speed, we need to:
Rational use of SSD capacity
Update firmware in time
Enable Trim Mode
Do not enable disk defragmentation
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