rqfr0tyBack in the early 1980s the use of a 32-bit MBR index was believed to adequate. Hard disks from the 1956 to 1981 had not even made it much past 1GB with mainframes.

The IBM 350 Disk Storage Unit (image), released in 1956, consisted of the magnetic disk memory unit with its access mechanism, the electronic and pneumatic controls for the access mechanism and a small air compressor. Assembled with covers, the 350 was 60 inches long, 68 inches high and 29 inches deep. It was configured with 50 magnetic disks containing 50,000 sectors, each of which held 100 alphanumeric characters, for a capacity of 5 million characters.

The IBM PC/XT (1983) offered a 5MB and 10MB disk while the PC/AT offered a 20MB hard disk. Disk capacity exceeded the MBR limit in 2011 with the introduction of 3TB hard disks. And capacity soon grew to 16TB when Samsung shipped their largest capacity SSD in 2016.

Early hard disks needed a controller card to manage them. The ST-506 standard (1980) was updated when ST412 RLL encoding was able to increase disk capacity by 50%. Finally, in 1986, IDE moved the controller onto the disk assembly and a new lower cost interface board make disks a lot less expensive. The low cost IDE port quickly was integrated into motherboards and the advent of the CD-ROM however created the need for a second EIDE port.

SCSI was popular in the 1980s with higher performance disks and CD-ROM drives. Early CD-R drives used SCSI which could provide sustained bandwidth that EIDE disks could not. Eventually disks and CD-ROMs were standardized and problems with the earlier hardware were eliminated. Some 16-bit sounds cards even had an EIDE port on them to support a CD-ROM.


Consumer hard disks are not designed for extreme workloads. Generally disks are designed for 55 TB per year. Exceeding that can degrade the AFR and shorten the service life of the disk. Generally this is only noticed when machines have inadequate RAM for the operating system and applications. Modern gaming machines now have at least 8GB of memory which eliminates a lot of disk swapping. Server disks are designed for larger workloads exceeded 200TB per annum.

Lossless audio can use TB of storage for larger iTunes collections. Compact disks tend to accumulate in storage boxes etc.

Reviewing catalogs of movies, its clear that racks of storage are needed for storing video archives. With over 3,500 movies on Blu-Ray it does take up a lot of storage. The largest disk is now up to 10TB so each hard disk can hold many movies. This means even consumers can now have huge collections of movies.

Low cost USB adapters mean old VHS tapes can be digitized and restored. These can then be placed into media libraries or archived to BDR disks.


We expect future hard disks to continue to increase capacity as new techniques come to market.

The current perpendicular magnetic recording technology (PMR) is running out of steam as continued size reductions in the magnetized bit area lead to unreliable data storage. Desktop disks have been using the technology since 2008. Areal density has reached 1TB per physical disk.

There are two long-term technologies suggested as a way to defeat this: heat-assisted magnetic recording (HAMR) and bit-patterned media (BPM).

Areal density could achieve areal densities of 4TB/sq2 and because of the large data reading, storing and rewriting operations needed when tracks are re-written they will require NAND flash on the disk drive on-board control. Hybrid drives are already starting to come to market.

Seagate sold about 585 million drives in 2013. Roadmaps for production through 2017 suggest hard disks are still being used in vast quantities. Corporate data warehouses are buying disks galore, some with over 1 million disks installed.

In 2013 the hard disk industry changed from the old 512 byte sector size to a larger 4096 byte format. This allowed the controller to use a more sophisticated algorithm to improved capacity while simultaneously improving error control.

Seagate suggested in 2013 that 60 TB drives will be available by 2020 by using newer techniques to store data. Huge capacity disks are would be ideal for a media library. In 2014, TDK announced  production of heads for HAMR disks expected in 2015.


Since the first PC back in 1980 the cost per GB or TB or PB has fallen 50% every 14 months. Using the standard regression for an exponential observation we can derive:

cost = 10-0.2502(year-1980)+6.304

Recently hard disk prices have fallen below 10 cents per GB. Eventually we expect to see hard disks fall below 1 cent per GB.

The real question is how far can technology push hard disk capacity into the future. Competition from flash memory definitely is giving the disk sector a lot of pressure to modernize.

hard disk price deflator over time


It was not until Windows 10 shipped that UEFI systems would finally be able to boot larger capacity disks. Before that the system disk was limited to 2TB which is the capacity limit for MBR partitions.

Video cards also need UEFI BIOS support as well. We were able to upgrade our GT 640 and GTX 660 Ti to UEFI. More recent cards are now finally shipping with UEFI capable video BIOS.

Our ST3000DM001 is installed as the boot disk. There is room for hundreds of games. Larger 4 TB disks and now 8 TB disks are available for extreme systems. Games can be installed on secondary disks easily.

Steam supports multiple storage volumes and addition game installs will be installed to the new location, unless it changed again.

We have numerous hard disks and Windows works fine with multiple disks installed in a machine. Games and programs can be installed on a second storage unit easily using a custom install.

Thief, Rage and Battlefield 3 are noteworthy as they each requires about 25GB. More and more games now ship on multiple DVD disks. The PC has been slow to adopt the Blue-ray disk used by consoles so many publishers have turned to digital distribution.

Most games are getting larger as the quality and detail in the artwork becomes increasingly sophisticated. For this reason using a very large disk is a good idea.

Today the largest individual 3½” 7200 rpm hard disk is 10 TB, there is room for 4 disks in the Corsair Carbide 300R.

Gaming machines are better off with the faster 7200 rpm models as these provide excellent sequential transfer rates. We buy disks frequently as prices continue to fall.

We should mention that SATA cables can be damaged. Replacing the cable should be the first thing done when disk errors are noticed and CHKDSK is not able to fix the problem.