A History of HDDs and SSDs

A History of HDDs and SSDs

Hard drive technology is relatively ancient (in terms of computer history). There are well-known pictures of the infamous IBM 350 RAMAC hard drive from 1956 that used 50 24-inch-wide platters to hold a whopping 3.75MB of storage space. This, of course, is the size of an average 128Kbps MP3 file, in the physical space that could hold two commercial refrigerators. The IBM 350 was only used by government and industrial users, and was obsolete by 1969. Ain't progress wonderful? The PC hard drive form factor standardized in the early 1980s with the desktop-class 5.25-inch form factor, with 3.5-inch desktop and 2.5-inch notebook-class drives coming soon thereafter. The internal cable interface has changed from Serial to IDE to SCSI to SATA over the years, but it essentially does the same thing: connects the hard drive to the PC's motherboard so your data can be processed. Today's 2.5- and 3.5-inch drives use SATA interfaces almost exclusively (at least on most PCs and Macs). Capacities have grown from multiple megabytes to multiple terabytes, an increase of millions fold. Current 3.5-inch HDDs max out at 6TB, with 2.5-inch drives at 2TB max.

The SSD has a much more recent history. There was always an infatuation with non-moving storage from the beginning of personal computing, with technologies like bubble memory flashing (pun intended) and dying in the 1970s and '80s. Current flash memory is the logical extension of the same idea. The flash memory chips store your data and don't require constant power to retain that data. The first primary drives that we know as SSDs started during the rise of netbooks in the late 2000s. In 2007, the OLPC XO-1 used a 1GB SSD, and the Asus Eee PC 700 series used a 2GB SSD as primary storage. The SSD chips on low-end Eee PC units and the XO-1 were permanently soldered to the motherboard. As netbooks, ultrabooks, and other ultraportables became more capable, the SSD capacities rose, and eventually standardized on the 2.5-inch notebook form factor. This way, you could pop a 2.5-inch hard drive out of your laptop or desktop and replace it easily with an SSD. Other form factors emerged, like the mSATA miniPCI SSD card and the DIMM-like SSDs in the Apple MacBook Air, but today many SSDs are built into the 2.5-inch form factor. The 2.5-inch SSD capacity tops out at 1TB currently, but will undoubtedly grow as time goes by.