Garbage Collection and TRIM in SSDs Explained – An SSD Primer
‘Garbage Collection in SSDs’ is a contributed article that was
submitted by LSI and authored by Kent Smith, Senior Director of
Product Marketing, Flash Components Division, LSI Corporation.
It’s importance cannot be understated for anyone venturing into
today’s world of SSDs. Garbage collection (GC) is a fundamental
process with all solid state drives (SSDs), but it can be
implemented in different ways that can impact the overall SSD
performance and endurance. In this article, we’ll look at how GC
works, how it can be implemented, and how it relates to the TRIM
command and over provisioning. Unlike hard disk drives (HDDs),
NAND flash memory cannot overwrite existing data they must first
erase old data before writing new data to the same location.
With SSDs, GC is the name for the process of relocating existing
data to new locations and allowing the surrounding invalid data
to be erased. Flash memory is divided into blocks, which is
further divided