click to visit home page
leading the way to the new storage frontier .....
SSD news since 1998
SSD news ..
image shows megabyte waving the winners trophy - there are over 200 SSD oems - which ones matter? - click to read article
top SSD oems ..
SSD jargon explained
SSD jargon ..
the fastest SSDs - click to read article
the fastest SSDs ..
image shows Megabye the mouse reading scroll - click to see the top 30 solid state drive articles
more SSD articles ...

By "SSD" nowadays (in 2017) I mean virtualized semiconductor memory systems which include controller IP to create a unique solution ready identity which is not simply a pass through transparency of the raw unimproved intrinsic memory.

SSD controller chips 1.0" SSDs M.2 SSDs consumer SSD
1.8" SSDs 2.5" SSDs 3.5" SSDs industrial SSDs
fault tolerant SSDs military SSDs RAM SSDs memory channel SSDs
There are lots of different types of SSDs
as you can see by clicking on the directory pages listed above

What's an SSD?

by Zsolt Kerekes, editor - first published in 2000

A solid state disk / drive (SSD) - is electrically, mechanically and software compatible with a conventional (magnetic) hard disk.

The difference is that the storage medium is not magnetic (like a hard disk) or optical (like a CD) but solid state semiconductor such as battery backed RAM, RRAM, PRAM or other electrically erasable RAMlike non volatile memory chip such as flash.

This provides faster access time than a hard disk, because the SSD data can be randomly accessed in the same time whatever the storage location. The SSD access time does not depend on a read/write interface head synchronising with a data sector on a rotating disk. The SSD also provides greater physical resilience to physical vibration, shock and extreme temperature fluctuations. SSDs are also imune to strong magnetic fields which could sanitize a hard drive.

The only downside to SSDs is a higher cost per megabyte of storage - although in some applications the higher reliability of SSDs makes them cheaper to own than replacing multiple failing hard disks. When the storage capacity needed by the application is small (as in some embedded systems) the SSD can actually be cheaper to buy because hard disk oems no longer make low capacity drives. Also in enterprise server acceleration applications - the benefit of the SSD is that it reduces the number of servers needed compared to using hard disk based RAID on its own.

Historically RAM based SSDs were originally faster than flash based products - but flash became the dominant memory in enterprise SSDs as a result of successive improvements in architecture during 2004 to 2015. (See sugaring flash for the enterprise for details.)

The reasons that users might benefit from buying SSDs are listed in the SSD Market Adoption Model.

Implicit in all my usages of the term "flash SSD" is the assumption that the device includes some form of controller which performs wear-leveling - as opposed to less smart flash memory storage which doesn't.

News about SSDs and a directory of all market active SSD oems can be seen on's main SSD page.

For other SSD related terms see - flash SSD Jargon.

Most of this definition (above) by was first published in 2000.

SSD ad - click for more info
here are some more SSD articles

the SSD story 1973 - 2017

2013 - SSD market changes

2014 - SSD market changes

2015 - SSD market changes

2016 - SSD market changes

SSD futures? - list of market analysts etc
Beware the distorting lens of viewpoint
as in - "SSDs are similar to..."
Can you trust SSD market data?
SSD ad - click for more info
In 2015, we put together a series of articles covering Solid State Drive technology, building from a single NAND cell to packaging, controller functions and SSD characteristics.
SSD 101 - an educational series for industrial system designers by Cactus Technologies
"Recently we've been hearing more details about the implementation plans for a new type of fast enterprise SSD - memory channel storage - aka ultra low latency SSDs."
ULL SSDs - PCIe SSD killers or collabrative co-workers?
SSD ad - click for more info
"Solid State Drives" is too limiting a term for the market segment. Emulating a spinning disk is a not a great aspiration for solid state technologies, which are radically higher performing. Then again, car engines are still measured in horse power!
Morgan Littlewood, VP Marketing and Business Development at Violin Memory (August 2007) - in the article:- RAM SSDs versus Flash SSDs - which is Best? - War for the datacenter core
It's by no means inevitable that the biggest memory companies will also go on to become the biggest SSD companies.
boom bust cycles in memory markets - an SSD view