Zettabytes of Storage

Total capacity of HDD shipped by the top three manufacturers reached an all-time high of 1 ZB in 2020.  A zettabyte (ZB) is a billion terabytes or a trillion gigabytes or a quadrillion megabytes.  In any case, it is mind blowing.

And, what's more mind numbing: capacity requirements are expected to triple between now and 2026 to over 3 ZB annually.

And, what's even more mind numbing is it only includes hard disk drives.  Solid State Drives (SSD) adds another 20% to the capacity number.

Do you remember the 1 GB hard drive in your 1995 PC?  I remember it was the largest available HDD for home computers at the time.  It would take a trillion of those disks to equal the capacity sold in 2020. 

Today's PCs and laptops seem to come standard with 1 TB hard drives.  It takes a billion of them to equal the 1 ZB capacity sold in 2020 alone.  And, repeat every year.  Just imagine someone buying a billion 1 TB disks each year.

Enterprise storage farms require much larger disks than your average PC or laptop.  Currently, the largest hard disk drive that I'm aware of is Western Digital's 18 TB HDD.  Larger drives satisfy the Digital Age's ever-increasing storage requirements.  Larger drives also slow the rate of data center sprawl and energy consumption.  Over the past 20 years capacity has increased by a factor of 5,000 so in theory we can store a lot more data in a lot less space using a lot less power and cooling.

Let's switch from capacity to quantity. 

The total number of hard disk drives (HDD) shipped by just the top three manufacturers in 2020 exceeded 260 million units.  This is actually down from 316 million disks in 2019.  In fact, the number of HDD shipped has dropped each year since its peak in 2010.  This is partly due to sales shifting to solid state drives (SSD) and non-volatile memory chips as a replacement to HDD in many applications like automotive and surveillance.  It's also partly due to the ever-increasing size of disks.  You can buy fewer disks each year and still get more total capacity.

The total number of SSD units sold in 2020 was about 333 million, which is 28% higher than the number of HDD units sold in the same period.  Total SSD capacity, however, was only 207 EB or about 20% of the 1 ZB HDD capacity sold in the same period.  This gap is likely due to the relative cost per gigabyte of SSD versus HDD storage with respect to the targeted application.  Generally, SSDs are still too pricy for archival storage or to replace near-line drives.  SSDs are a dominant force in enterprise databases and are increasingly sold into IoT, edge, automotive, gaming, and consumer electronics.

In case you're wondering who were the top three HDD manufacturers in 2020 and their market shares: Seagate leads with 43%, WD comes next with 37%, and then Toshiba with a respectable 20%.  The numbers flip around each year, and of course it depends if you're counting units or capacity.