What does TBW mean in SSD storage, and what is its importance?
No one denies the importance of speed in any computer , and one of the speed factors - that is not talked about enough - is TBW, which is the speed of the SSD solid state storage unit . What is it and what is its importance? This is what we will discuss in our article today. Let's go.
Whether you want to download the latest AAA games or deal with huge files, of course you need your computer components to be high-speed, but when it comes to storage capacity, it's more important than you might expect, and that's where Total Bytes Written (TBW) comes in.
One of the factors that cause damage to motherboards is the use of cheap power supplies, or the processors heating up due to excessive speed, but this is not the case with storage units. When the hard disk or SSD is damaged, if you do not have a backup copy, it may cause your data to be lost forever, including photo files, videos and work files. What we mentioned earlier explains the importance of backups, and now we will learn about the importance of something else, which is TBW and its importance in SSD.
What is TBW?
TBW, or Total Bytes Written, is a metric usually measured in terabytes that is assigned to storage devices to tell you how many terabytes you can write to the disk during the warranty period before the memory cells start to degrade and the possibility of data loss and the entire disk being damaged increases, at which point it alerts you to replace the disk because your data is no longer safe and is at risk of being damaged and lost.
TBW is distributed over the warranty period of the disk, which is usually 3 or 5 years, and TBW numbers can range from 30 TB on some disks to several thousand TB on others. The warranty covers the data you can write to the disk during the years that the SSD can operate without damage.
What is DWPD?
Data Write Per Day, or DWPD, is how much data can be written each day of a disk's warranty period. This number is typically expressed in tens or hundreds of gigabytes. Although DWPD is commonly used in enterprise settings, it is the more accurate of the two readings as some manufacturers do not take disk capacity into account when calculating TBW numbers.
How does TBW affect storage?
Solid state drives, whether traditional 2.5-inch drives or the newer M.2 and PCIExpress drives, rely on the same basic technology: NAND flash memory, paired with a controller that helps locate data when writing and later finds it when reading.
But of course, this speed comes at a cost. As flash memory wears down with use, each cell in each memory chip can only be written to a limited number of times before it is about to fail. There are several reasons for this, from memory wear to reading errors, but suffice it to say that flash memory has a limited lifespan. This is where TBW comes in. It is a measure of this lifespan, and it is directly affected by the rate at which the memory cells in it deteriorate. In addition to how the disk is used, there are several factors that cause disk failure.
SSD disk failure factors
To avoid SSD damage, proper methods should be followed when using it and proper operating conditions should be provided, such as maintaining a moderate temperature and using stable power sources. In addition to how the drive is used, there are many factors that contribute to the rate of this degradation.
1- Type of memory cell used
One of the most important factors is the type of memory cell used. Single-level cell (SLC) memory can only hold one bit per cell, while multi-level cell (MLC) memory has two, and triple-level cell (TLC) memory has three bits per cell. Quad-level cell (QLC) memory can hold four bits per cell. This certainly gives it the ability to handle four times the amount of data compared to traditional SLC flash memory in the same space, but it is usually slower and has worse efficiency.
2- Temperature
Temperature also causes disk wear, however, it is not controlled by the manufacturer and does not reflect the total amount of data written (TBW). Most SSDs generate very little heat, so as long as there is adequate ventilation, there is no need to worry. Crucial is one of the best companies in the field of manufacturing and distributing memory modules and solid state drives (SSDs).
Techniques that help improve TBW
To increase the operating life of SSDs, manufacturers come up with a number of technologies that contribute to a safer lifespan of the device.
- Over-allocation is one of the most common techniques, which involves removing user access from a set of memory cells to use as temporary data storage, which is one reason why the capacity of an SSD used is often less than what is shown in the operating system, for example, a 500GB SSD may only be shown as 465GB.
- TRIM is a data cleansing method controlled by the operating system, which can inform the SSD which data cells can be completely erased and written without having to read the data first, improving the disk's lifespan and TBW (total bytes written).
How to choose TBW?
Total Bytes Written (TBW) numbers can vary from storage device to storage device and are often associated with warranties of different lengths depending on price, quality, and manufacturer policies, but the number of gigabytes a storage device can deliver per day can be considered based on its specified TBW value, using the calculation of dividing the TBW by the warranty period in days.
When it comes to choosing the right SSD and TBW, estimate how frequently you will write data and how much data you think you will be writing to it, and factor that into your purchasing decision.
How many GB to write to SSD per day?
Although hard drive usage varies from person to person, the average is between 10 to 35 GB per day, and if this amount is increased to 40 GB, it may be written for more than five years before reaching the SSD TBW limit of 70 TB.
Also, the average TBW statistic for a 250GB SSD is between 60 and 150TB written, indicating that it has exceeded the specified TBW of 70TB.
What happens if the SSD exceeds the allowed TBW limit?
Many people think that SSD will be damaged once the TBW limit is exceeded, but this is not entirely true, after the TBW runs out the SSD will retain its data, which you can access at any time but the write functions will not be accessible and the SSD warranty will be over.
People who use their SSDs for a long time usually exceed these limits, but in rare cases SSDs may stop writing before reaching the limit but this will take several years as some people use SSDs for 5 to 10 years without any problems.
It is important to remember that TBW and DWPD are just estimates and that memory cells may have expected variance in lifespan and quality, while both numbers are an important measure of how long a disk will last. However, purchasing an SSD with a high TBW will definitely ensure a longer lifespan than one with a low TBW.