Computer Basics: Storage

By Martin Jansen, Owner of Jansen-PCINFO

Perhaps no technology has increased rapidly in sophistication than computer storage.  It used to be that computer hard drives (HDs) ruled in personal computers.  These drives have mechanical read/write heads floating above magnetic platters retrieving and writing data at the command of the user and operating system.  The platters spin rapidly on a spindle from 4500 to 7200 revolutions per minute.  Spindle speed greatly affects how quickly the data can be transferred.  These drives usually came in the 3.5 inch form factor as shown in the first image above.

Computers with a single hard drive stores the operating system, local data and, in modern computers, UEFI (Unified Extensible Firmware Interface) data which augments the Basic Input and Output System (BIOS).  Unlike RAM, which is temporary storage when the computer is on, the data on hard drives is retained when the computer is off.

When I first started supporting business computers, 40 GB hard drives were the norm.  As time went on the storage capability doubled and then doubled again.  Soon 500 GB HDs became the norm with 1 terabyte (TB) drives coming after.  Now it is possible to have 2 and 4 TB drives in personal computers with major storage in the 16 TB range.

Solid State Drives (SSD)

While hard drives have great storage capabilities, SSDs are much faster.  Unlike mechanical drives, SSDs have no moving parts.  Transfer rates are about 125 megabytes per second for 7200 rpm HDs vs 500 mbps for SSDs.

SSDs are a drop-in laptop replacement for HDs as they have the same 2.5 inch form factor.  This means that even older computers can be made three times faster just by replacing the hard drive.  Computers boot faster, operating systems become available sooner, software loads faster and people are happier with SSDs vs HDs.

The big difference, however, is the storage size per dollar.  A new Seagate 1 TB HD costs about $50 while a SSD drive of equal capacity costs $100 for a Samsung EVO.  As with all technology the prices for SSDs have steadily dropped since they were first introduced in 2006.

Many desktop users have replaced HDs with SSDs to run their operating system while keeping their larger capacity HDs for storage of videos and other large files.

Even Faster with NVMe

SSDs are fast, but the Serial Advanced Technology Attachment (SATA) interface is now a barrier to even greater speeds.   NVMe drives are smaller and connect to the PCIe interface, with speeds approaching 5,000 megabytes per second.  You read that right.  NVMe drives are theoretically 10 times faster than SSDs.

In case you are interested, NVMe stands for Non-Volatile Memory express (the small e is for the interface type).

NVMe drives are relatively new, first introduced in 2016, and can only be used in an interface card in older computers.  Computer manufacturers are now regularly incorporating NVMe interfaces and drives in their laptop computers.  For desktop computers, NVMe interfaces are also being added to motherboards.

Conclusion

Computers are getting smaller, lighter and more efficient as time goes on.  Heavy 3.5 inch hard drives have been replaced by lighter 2.5 inch models.  Succeeding hard drives are Solid State Drives which again are lighter and the newest and lightest of all are NVMe drives.  The future of storage will see increased capacity and will involve AI technology where the interface will anticipate the data needs of the user.  Cloud storage will continue to increase as well in data centers around the world, decreasing the need for local storage.