magnetic tape

Magnetic tapes today

Magnetic tapes have come a long way since the first tapes 1930 and many advantages (like the high recording density) they once possessed are long gone. Modern hard disks have significantly improved recording methods compared to magnetic tapes. They can also reach enormous data rates and, because they do not have the impractical sequential access, a faster access time. Magnetic tapes are still used to this day, but they are getting slowly replaced by other data storage devices that do not share the disadvantages the magnetic tapes possess (like the comparable high access time compared to CD´s or USB drives).
But because of their lower costs per bit they are still a good alternative to other data storage devices like CD´s/DVD´s. This is a big advantage when there are huge amounts of data to save. Another good use for magnetic tapes is for data that needs to be in storage for a longer time, because that way the data don´t need to be saved on more expensive storage devices that constantly uses energy to function (magnetic tapes don´t need energy to save/storage data). In case there are data that are needed to be accessed more often, magnetic tapes are not a good choice. There are several reasons for this. One: Magnetic tapes have a higher access time compared to other devices. And two: if data needs to be often accessed/written the magnetic layer wear out fast.
But magnetic tapes are still used because of their high reliability and a long duration during which it can be guaranteed to retain the data stored on the media. They are mainly used for long time data storage and to data backup.

It has been proven that the need for more data to save/storage steadily increases and therefore the need for mainly cheap storage media also increases. Magnetic tapes are a good use for this because of their comparable low costs and their long viability. Their high data density is another advantage (depending on intended use of the data up to 1000GB can be saved). Huge amounts of data can be saved on a lot smaller room this way. Other costs can also be reduced because with magnetic tapes you need only to pay for the storage. Hard disks needs to be put in rotation at least twice a year or else the liquid hardens and the hard disks malfunctions. Because of that you need to pay additional amounts of money for it.
Another area of use for magnetic tape is long time storage of data. There is a significant difference between storage and data backup. The main aspect for data backup is the external data storage, while for long time storage it is mainly important to storage safely over a long time. The advantages of low costs and long lifespan are again in use. Magnetic tapes can be easily transported and stocked. A long time storage for magnetic tapes is not problematic compared to hard disks. Under the right conditions and few Write/Read accesses, a lifespan of about 30 years is guaranteed. In the future the data density will be significantly increased. At least that is what the future developments are about.
The magnetic layer is mainly responsible for the data density. Through the use of smaller particles, from not yet used materials, layers with very high densities can be created. IBM, in cooperation with Fuji Photofilm created a test tape with never before achieved data density. On such a tape up to 8 TB of compromised data can be written. But it will take a few years before it can be commercially sold (actual guesses are about 5 years). Other researches are done to further increase the viability of the magnetic layer and therefore increase the overall lifespan of magnetic tapes.
A conductive coating of the backside increases the viability of modern tapes. Static electricity derives via this coating from the non-conductive backside what hinders a influence on the magnetization by the static electricity. To prevent the tapes from breaking apart there are researches done to improve the binder of the tape. This will improve the resistance to temperature influences and moisture.

In summary it can be said that magnetic tapes do not belong to the past. In 2010 the Paul Scherrer Institute(PSI) and the german Universität Konstanz took tests to develop a new magnetic tape which could replace hard disks entirely in the future. These new magnetic tapes (called Racetracks) do not only have very high data densities, they also have way faster access times than other modern data storage devices (source: PSI).
The information (in magnetic bits) are saved like on any other magnetic tape on a wire. But unlike conventional tapes the wire isn't moved mechanically over the Writing/- Reading heads. Instead a magnetic field pushes the bits through the wire. By using a tiny nanowire many racetracks can be saved in intervals of few hunderts nanometres. This means good data densities that could surpass even typical USB-sticks.