So, however advanced may be the technology used in CPU production, it will be ineffective if technology for storage media is not developed to the same extent.



A great possibility towards achieving this goal comes from some new kinds of digital storage devices that are going to emerge in the future. These include:

Holographic Memory

This technology is based on optical recording which is also known as Holography. It allows high record density along with maximum data access speed. It is based on the principle that the holographic image is coded in one big data block which is recorded and read in single access.

It is stored on a light sensitive material and lasers are used to write or read them. Theoretically speaking, it will allow thousands of digital pages with millions of bits each, to be stored in a device as small as a grain of sugar. Theoretically, the data density is going to be 1 Tbytecm3. Practically, it is expected to be at least 10 Gbytescm3, which is impressive compared to the present density of several Mbytescm2. Also, the present devices have the feature of collective block access missing from them.

Thus, such a recording density will allow an optical layer of about 1 cm in width to keep around 1 Tbytes of data. Also, there are going to be no moving parts and a parallel access of pages will be allowed. Since the interference patterns fill up the optical layer uniformly, it gives another useful property to the holographic memory - high reliability of the recorded information. While a defect on the surface of the magnetic disc or tape destroys important data, a defect in holographic medium only tarnishes the hologram. As against the hard drive of today which is the main source of power consumption, it saves on power consumption.

Molecular Memory

Another approach in the creation of storage devices is the molecular method. It is based on a prototype of memory subsystem which uses digital bits of a molecule. These are protein molecules which is called Bacteriorhodopsin. It's purple, absorbs the light and is present in a membrane of a microorganism called Halobacterium Halobium. Its photo cycle, the sequence of structural changes a molecule undergoes in reaction to light, makes it an ideal AND data storage gate, or flip-flop. According to research, the bR (where the state is 0) and the Q (where the state is 1) intermediates are both stable for many years.

Both, bR and Q, have different absorption spectra which helps define the current state of the molecules with the help of a laser set for definite frequency. The prototype of memory system resembles a cuvette (a transparent vessel) filled up with polyacryde gel, where the protein is put. Theoretically, the cuvette can accommodate 1TBytes of data. Limitation of capacity is mainly related to problems of lens system and quality of protein.

Molecular memory has advantages over traditional semiconductor memory. First, it's based on protein which is produced in large volumes and at a low price. Secondly, the system can operate in a wider range of temperatures than the semiconductor memory. Thirdly, data is stored constantly; even in case of power switching off, it won't cause data loss. And finally, bricks with data which are rather small in size but contain gigabytes of data are easy to store. Since the bricks do not have moving parts, it's more convenient than usage of portable hard discs or cartridges with magnetic tape.

MRAM

Memory chip manufacturers have been seeking technology that will be faster, smaller, cheaper and retain data when the power is off. They have found it in MRAM chips. This is radically new technology. People have been dabbling in this for years, but nobody has been able to make it in volume. The chip, called magneto resistive random-access memory (MRAM), maintains data by relying on magnetic properties rather than an electrical charge.

The benefit of MRAM chips is that they hold information after power has been switched off. Unlike flash memory, which can also keep data without power, MRAM has faster read and write speeds and does not degrade over time. Furthermore, information can be stored in an MRAM memory cell up to one million times more often than is possible with flash memory. It eliminates the boot-up phase since the computer retains the current state of work and its non volatility consumes less power than the traditional DRAM.