What is Write Amplification?

A 4x4 checkerboard of red, green, and white squaresFor a long time, The SSD Guy has been talking about Write Amplification without explaining what It is.  This post is intended to fix that.

Write amplification is an internal issue for NAND flash SSDs that arises from the way that NAND chips work.  It doesn’t exist in standard HDDs, nor did it exist in DRAM SSDs before we had NAND ones.  In a nutshell it’s the Continue reading “What is Write Amplification?”

Mardi Gras vs. SSD Garbage Collection

Silhouette of a hopping rabbitMardi Gras is a good time for The SSD Guy to bend your mind.  It’s the day before Ash Wednesday kicks off Lent, which is the official start of the Easter season.

And it never seems to happen on the same date.

I will compare SSD garbage collection to the timing of the Easter season.  There are surprising similarities.

Very few people understand Continue reading “Mardi Gras vs. SSD Garbage Collection”

Smarter NAND for Better SSDs

NAND part of one of the diagrams below.Micron presented something really interesting during the company’s Investor Day Conference last week, but it didn’t seem to get any press coverage.  The company naturally repeated its plan to become a more important supplier of data center SSDs, but what The SSD Guy was most interested in were a few comments they gave for choosing to make vertically-integrated SSDs.  Micron now makes not only the NAND and the DRAM internal to its SSDs, but also the controller.

Why would a company Continue reading “Smarter NAND for Better SSDs”

Whatever Happened to “Hero” SSDs?

Bodybuilder with the insides of an SSD superimposedIt seems not so long ago that there were frequent press releases, and showings at trade shows, of “Hero” SSDs.  These demonstration models (which weren’t always released as products) always had some unique and impressive attribute.  They may have had a higher capacity than any SSD known to humankind, or perhaps they had phenomenal endurance.  Some broke the IOPS barrier.

The SSD Guy doesn’t remember anyone Continue reading “Whatever Happened to “Hero” SSDs?”

Using 176-Layer NAND for High-Capacity Data Center SSDs

Chart with a line that goes pretty flat from 1.5 to 2ms latency 0 to 350K IOPSMicron recently briefed The SSD Guy on its new 7450 SSD series, a range of high-capacity data center SSDs offered in an impressive number of capacities and form factors spanning M.2, U.3 and E1.S. The 7450 is a mainstream drive targeted at a wide variety of data center applications, including common, mixed, and random workloads.

The 7450 series is an evolution of Micron’s 7400 series which was first introduced at 96 layers and was based on Continue reading “Using 176-Layer NAND for High-Capacity Data Center SSDs”

Using AI to Manage Internal SSD Parameters

Old wise man with a disk symbol coming out of his headFor a long time The SSD Guy has meant to write something about the budding use of AI in SSDs.  It’s an interesting approach whose time has come.

If you’re not conversant with AI, and maybe find the whole subject to be daunting, don’t worry.  AI comes in many forms, and some are very simple.  When major Internet firms like Google and Facebook use AI to Continue reading “Using AI to Manage Internal SSD Parameters”

What’s Software-Enabled Flash?

abstract eye-catching imageThere have been numerous changes to SSDs since they moved into the mainstream 15 years ago, with controllers providing increasing, then decreasing endurance levels, and offering greater, then lesser levels of autonomy.  What has been missing is any ability for the system to determine the level of performance that the SSD provides.

Recently Kioxia, the company formerly known as Toshiba Memory, announced Continue reading “What’s Software-Enabled Flash?”

Micron’s New XPoint SSD Finally Arrives

Micron X100 3D XPoint SSDAt its October Insight Conference Micron Technology finally revealed its 3D XPoint SSD, dubbed the X100.

While the company didn’t disclose too much about the device, it did brag about its speed, claiming that the X100 is the world’s fastest SSD, running three times faster than the fastest NAND flash SSDs and almost three times the speed of other XPoint SSDs.  The product is said to Continue reading “Micron’s New XPoint SSD Finally Arrives”

The Memory/Storage Hierarchy

Memory/Storage ThumbnailIt recently dawned on me that one of the charts that I most frequently use in my presentations has never been explained in The SSD Guy blog.  This is a serious oversight that I will correct with this post.

The Memory/Storage Hierarchy (also called the Storage/Memory Hierarchy, depending on your perspective) is a very simply way to Continue reading “The Memory/Storage Hierarchy”

Failure is Not an Option — It’s a Requirement!

I was recently reminded of a presentation made by GoDaddy way back in the 2013 Flash Memory Summit in which I first heard the statement: “Failure is not an option — it is a requirement!”  That’s certainly something that got my attention!  It just sounded wrong.

In fact, this expression was used to describe a very pragmatic approach the company’s storage team had devised to determine the exact maximum load that could be supported by any piece of its storage system.

This is key, since, at the time, GoDaddy claimed to be the world’s largest web hosting service with 11 million users, 54 million domains registered, over 5 million hosting accounts, with a 99.9% uptime guarantee (although the internal goal was 99.999% – five nines!)

The presenters outlined four stages of how validation processes had Continue reading “Failure is Not an Option — It’s a Requirement!”