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?”

Would WDC Really Merge with Kioxia?

Column Chart comparing WDC's and Kioxia's margins for the past 12 quartersEver since Toshiba decided to spin out its memory business in 2017, leading to the creation of Kioxia, there have been rumors of Western Digital (WDC) acquiring it, or of Kioxia acquiring WDC’s flash memory business.

There is a new spate of merger rumors in response to Elliott Management’s proposal last May that Continue reading “Would WDC Really Merge with Kioxia?”

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”

Another Perspective on a WDC Split

Western Digital logo splitting int the WD logo and the SanDisk logoIn an earlier post I reacted to a letter that activist shareholder Elliott sent to Western Digital’s board asking for the company to be split into two parts, one for HDDs and the other for flash.  I wrote it before learning that the Elliott letter was posted on the web for public viewing.

I found Elliott’s proposal hard to rationalize.

Although the reasoning I shared in that post is Continue reading “Another Perspective on a WDC Split”

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”

WDC: To Split, or Not to Split?

Photo of log being split with an axeWestern Digital’s Board of Directors was recently sent a letter by activist shareholder Elliott asking for the company to be split into two parts: one for HDDs and one for flash.  The reason given was that the company’s SanDisk acquisition was not performing well.

Elliott currently holds a 6% stake in WDC.

According to an article in Reuter’s, Elliot’s letter said: Continue reading “WDC: To Split, or Not to Split?”

Should WDC Acquire Kioxia?

Single star from the post's second chart.Over the past couple of months rumors asserted that Western Digital (WDC) was in talks to acquire joint venture partner Kioxia.  This is not the first time such rumors have emerged.  In November of 2020, when Kioxia was expected to make its initial public offering, WDC was rumored to be in such talks, and before that, in early 2017, when Toshiba first started to plan to spin off its NAND flash and SSD business, WDC was rumored to Continue reading “Should WDC Acquire Kioxia?”

Micron’s Tiny Little 2TB SSD

Photo of top of tiny m.2 SSDMicron has been moving very quickly for the past couple of years, and that has led to the company’s undisputed leadership in NAND flash layers and DRAM process nodes.  The first to ship 176-layer NAND flash chips a year ago, and now 176-layer QLC NAND, Micron packs a huge amount of storage into a single chip.  Since it uses a CUA (CMOS Under Array) architecture, the die size is perhaps Continue reading “Micron’s Tiny Little 2TB SSD”

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”

Solidigm, SK hynix’ New SSD/Flash Subsidiary

Solidigm LogoWhile many of us, The SSD Guy included, were preparing for our New Year’s celebration, SK hynix, on December 30, closed the first phase of the company’s takeover of Intel’s NAND flash and SSD business, and created a new subsidiary that has been named Solidigm.

This is the first of two phases of the acquisition, which the companies agreed to in October 2020.  With this move, SK hynix has Continue reading “Solidigm, SK hynix’ New SSD/Flash Subsidiary”