Garbage Collection
GC is the storage capacity management mechanism for the main component of an SSD, i.e., the process of transferring the data stored at a particular Block to another Block of the NAND Flash while erasing non-useful data.
As NAND Flash is unable to overwrite previously stored and ineffective data, the original ineffective data in the Block must be erased before new data can be written in. However, the smallest write-in unit for NAND Flash is Page, and the minimum unit of erasure is Block; each Block contains 64 or 128 Pages, which means that data erasure is carried out by the Blocks.
Garbage Collection 10GC simply duplicates the effective data from Blocks and integrates into another available Block when there is ineffective data required to be erased; therefore, the by-the-Block erasure can be carried out to form a Free Block.
Garbage Collection 12If within Block X, there are data in the 6 Pages of A to F, if A, B, and C needs to be revised as A’, B’ and C’; the data in D, E, and F needs to be erased, then the SSD shall operate in the following:
(1) Save A’, B’, and C’ into the Free Page, while mark A, B, C, D, E, and F as Garbage
(2) Then save A’, B’, and C’ in the free Page of Block Y
(3) Execute Garbage Collect, and erase the entire Block X, and all Pages become Free Page.
The objective of GC is to continuously clear out more free Blocks to maintain the write-in function of the SSD, as the more there are free Blocks, the faster the write-in speed will be. However, the P/E Cycle of NAND Flash Block has limits. If a single Block is subjected to constant write-in and erasure, there will be excessive wear and loss. This ultimately leads to decreased read-write speed, or worse, it may lead to damage, which results in a Bad Block.
SATA SSD
40GB / 80GB / 160GB / 256GB / 320GB / 640GB
NAND Flash: 3D pSLC(TLC)
Interface: SATA 3 (6Gb/s)
Sequential Read: UP to 550 MB/s
Sequential Write: UP to 510 MB/s
SATA SSD
120GB / 128GB / 256GB / 480GB / 512GB / 960GB / 1024GB / 2048GB
NAND Flash: 3D TLC NAND Flash
Interface: SATA 3 (6Gb/s)
Sequential Read: UP to 550 MB/s
Sequential Write: UP to 510 MB/s
NVMe™ SSD
80GB / 160GB / 320GB
NAND Flash: 3D pSLC(TLC)
Interface: PCIe® Gen4 x4
Sequential Read: UP to 3700 MB/s
Sequential Write: UP to 2600 MB/s
NVMe™ SSD
40GB / 80GB / 160GB / 320GB / 640GB /1280GB
NAND Flash: 3D TLC NAND Flash
Interface: PCIe® Gen3 x4
Sequential Read: 3,100 MB/s
Sequential Write: 1,500 MB/s
NVMe™ SSD
40GB / 80GB / 160GB / 320GB / 640GB /1280GB
NAND Flash: 3D TLC NAND Flash
Interface: PCIe® Gen3 x4
Sequential Read: 3,100 MB/s
Sequential Write: 1,500 MB/s
NVMe™ SSD
80GB / 160GB / 320GB
NAND Flash: 3D TLC NAND Flash
Interface: PCIe® Gen4 x4
Sequential Read: UP to 3,500 MB/s
Sequential Write: UP to 2,100 MB/s
NVMe™ SSD
128GB / 256GB / 512GB / 1024GB / 2048GB /4096GB
NAND Flash: 3D TLC NAND Flash
Interface: PCIe® Gen3 x4
Sequential Read: 3,100 MB/s
Sequential Write: 1,500 MB/s
NVMe™ SSD
128GB / 256GB / 512GB / 1024GB / 2048GB /4096GB
NAND Flash: 3D TLC NAND Flash
Interface: PCIe® Gen3 x4
Sequential Read: 3,100 MB/s
Sequential Write: 1,500 MB/s
NVMe™ SSD
256GB / 512GB / 1024GB / 2048GB
NAND Flash: 3D TLC NAND Flash
Interface: PCIe® Gen4 x4
Sequential Read: UP to 6,800 MB/s
Sequential Write: UP to 4,800 MB/s
NVMe™ SSD
240GB / 256GB /480GB/ 512GB / 960GB/ 1024GB
NAND Flash: 3D TLC NAND Flash
Interface: PCIe® Gen4 x4
Sequential Read: UP to 3,700 MB/s
Sequential Write: UP to 2,600 MB/s
NVMe™ SSD
256GB / 512GB / 1024GB
NAND Flash: 3D TLC NAND Flash
Interface: PCIe® Gen4 x4
Sequential Read: UP to 3,700 MB/s
Sequential Write: UP to 2,600 MB/s
NVMe™ SSD
128GB / 256GB / 512GB
NAND Flash: 3D TLC NAND Flash
Interface: PCIe® Gen3 x4
Sequential Read: UP to 2,000 MB/s
Sequential Write: UP to 1,100 MB/s
NVMe™ SSD
128GB / 256GB / 512GB/ 1024GB
NAND Flash: 3D TLC NAND Flash
Interface: PCIe® Gen3 x4
Sequential Read: UP to 2,000 MB/s
Sequential Write: UP to 1,100 MB/s
NVMe™ SSD
128GB / 256GB / 512GB
NAND Flash: 3D TLC NAND Flash
Interface: PCIe® Gen3 x4
Sequential Read: UP to 3,700 MB/s
Sequential Write: UP to 2,600 MB/s
SATA SSD
128GB / 256GB / 512GB / 1024GB
NAND Flash: 3D TLC NAND Flash
Interface: SATA 3 (6Gb/s)
Sequential Read: UP to 550 MB/s
Sequential Write: UP to 510 MB/s
NVMe™ SSD
128GB / 256GB / 512GB
NAND Flash: 3D TLC NAND Flash
Interface: PCIe® Gen3 x4
Sequential Read: UP to 2,000 MB/s
Sequential Write: UP to 1,100 MB/s
SATA
128GB / 256GB / 512GB / 1024GB
NAND Flash: 3D TLC NAND Flash
Interface: SATA 3 (6Gb/s)
Sequential Read: UP to 550 MB/s
Sequential Write: UP to 510 MB/s
SATA SSD
240GB / 480GB / 960GB / 1920GB / 3840GB
NAND Flash: 3D TLC NAND Flash
Interface: SATA 3 (6Gb/s)
Sequential Read: UP to 520 MB/s
Sequential Write: UP to 520 MB/s
SATA SSD
240GB / 480GB
NAND Flash: 3D TLC NAND Flash
Interface: SATA 3 (6Gb/s)
Sequential Read: UP to 520 MB/s
Sequential Write: UP to 520 MB/s
SATA SSD
240GB / 480GB / 960GB / 1920GB
NAND Flash: 3D TLC NAND Flash
Interface: SATA 3 (6Gb/s)
Sequential Read: UP to 550 MB/s
Sequential Write: UP to 450 MB/s
SATA SSD
128GB / 256GB / 512GB / 1024GB / 2048GB
NAND Flash: 3D TLC NAND Flash
Interface: SATA 3 (6Gb/s)
Sequential Read: UP to 550 MB/s
Sequential Write: UP to 510 MB/s
SATA SSD
128G / 256GB / 512GB / 1024GB / 2048GB
NAND Flash: 3D TLC NAND Flash
Interface: SATA 3 (6Gb/s)
Sequential Read: UP to 550 MB/s
Sequential Write: UP to 510 MB/s
__24C15hqqtC.png)
__24C15wOdCC.png)
__24C05XQ2my.jpg)
__24C05fplcZ.png)
__24C05vgHYC.png)
