UFS, or Universal Flash Storage, is a specification for flash storage devices used in mobile electronics such as smartphones, tablets, notebooks, digital cameras, and more. As the UFS standard is significantly faster and can be used in both internal and external applications, it’s expected to replace storage specifications such as eMMC (internal) and SD Card (external).
UFS 1.0/1.1Maximum Bandwidth: 300 MB/s
UFS 2.0/2.1Maximum Bandwidth: 1,200 MB/s
Wear leveling is a technique that extends the lifespan of an SSD by distributing write operations equally across all blocks of NAND.
This is important because all NAND flash memory produced today have a limited number of erase/write cycles. Once the endurance limit has been reached, the expired blocks would no longer be able to be rewritten with new data.
To preserve the limited number of erase/write cycles, the SSD controller doesn’t actually perform an erase operation on a data block when it’s issued a deletion command. Instead, it simply marks the block as invalid, which simply means that the data can be safely overwritten.
When a new write [...]
Price/GB is a simple ratio for measuring the price of any storage device. It’s calculated by dividing the cost of the drive by its capacity. The lower the number, the better.
Over-provisioning in SSDs is a method of maintaining SSD performance and increasing SSD endurance by either allocating a portion of NAND to be used as “swap space” when the drive is at capacity or as a replacement for degraded NAND cells.
Currently, consumer SSDs generally feature 7% over-provisioning while enterprise SSDs generally feature 28% over-provisioning. Some enterprise SSDs however, have been known to have over 50% over-provisioning for improved write endurance.
TRIM, when used in the context of storage devices, refers to the TRIM command in the ATA command set and the UNMAP command in the SCSI command set.
TRIM commands are typically used with SSDs. SSDs require TRIM because of a fundamental way of how SSDs operate. Unlike HDDs, SSDs can only program or erase the data in a NAND cell. Because of this, when overwriting or re-programming a cell, SSDs need to go through an erase program cycle which takes longer than a simple program cycle.
The TRIM command is designed to let the SSD controller know which blocks of data on the SSD is no longer valid. On its own, the SSD controller does not know the file structure of the [...]
Write amplification is an undesired phenomenon in SSDs when more writes to the NAND occurs than necessary. Due to most NAND having a limited number of write/erase cycles, high write amplification could significantly impact the lifespan of an SSD.
Write amplification could happen in a variety of ways, but the most common way it can occur is the way the SSD handles modifications to a specific block of data. Storage blocks are divided into pages, and pages within the SSD can’t be deleted individually. This means that whenever a few pages need to be altered, all the old data within the block needs to be erased and rewritten to include the modified data, wasting [...]