Memory types and its features

Memory types and its features

      In computers, Hard Disc drives, Pen Drive, RAMs are mainly used.  These memories are made of different technology. These are  Hard drive, SRAM, DRAM, Flash memory and MRAM.  Now a days, the hard disc drives are available at higher densities in the order of more than 500 GB. The flash pendrives are at higher densities of order of 16, 32 GBs and the size is also very very small. The features of these memories and its positive and negatives are given here

1. Hard drive:
High density, very low cost per byte stored, high power.
Moderate read and write speeds and bulky moving parts.

2. SRAM :
Super fast read and write speeds and low power consumption
Large memory cells take up more space, volatile

3. DRAM: High density, low cost, fast read and write speeds and low power
Volatile and require constant refreshing of data drains power

 4. Flash:
Nonvolatile, High density, fast read speed
More power consumtion, write operation is slow and limited life time

5. MRAM:
Non volatile, high density, fast read and write  speeds, low power and unlimited lifetime

Spin transistors to keep Moore's Law and Spin Memory future memory of the world of electronics

Spin transistors to keep Moore's Law and Spin Memory future memory of the world of electronics

The transistor densities in a single chip has been increased and designed to keep the Moore's law lively. However with today's technology, the trend  has to change otherwise at one point the quantum effects will not permit and Moore's law can not be meet out. In order to overcome this problem, the spintronics technology which is spin based electronics, is going to take over the conventional chip technology.

Basics of Spin electronics Technology:

Spin is a basic unit of quantum properties of electron  and sub atomic particles. Spin can have two states relative to a magnetic field which is referred as up and down. These two states can be represented as two values of binary (0 and 1) for storing a bit. We can manipulate these states which is faster and required less energy and can take smaller scales. Hence, chips can be built with spin transistors which are so faster and more powerful than the traditional transistors. 

Spin Memory                                                 Image courtesy: IEEE Spectrum Magazine.

Spin Memories are built with the spintronics technology called as MRAM (stands for Magneto resistive RAM) . This MRAM stores the bits in a ferromagnetic substance  in which data bits are stored by making alignment of electrons in one directions or others. The spin up means 0  and spin down means 1. With this technology, we can perform erase, read and write operation. 

The features of spin memory are

High densities, 

fast read and write speeds, 

low power consumption and 

unlimited write operation possible. 

It can be used as a universal nonvolatile memory.

Dimension in the order of 150nm.

For further information, read the IEEE Spectrum Magazine.

Algae - A new alternative renewable bio fuel

Algae - A new alternative renewable bio fuel
   The renewable sources such as energy from solar, wind, tidal and bio fuels have been gaining momentum for replacing conventional fuels (fossil fuels) and fight against the global warming problems. Such one alternative is algae, a bio fuel to provide a renewable source for diesel, gasoline and jet fuels. 
   Algae (like plants) are micro organisms which use the photosynthesis to convert light into chemical energy and with the advantages absorbing Co2 from the surrounding atmosphere. Initial stage, algae turn carbon that it take into sugars and then into oil which can be used as fuel.The algae grow rapidly and can be reaped continuously, so high amount of oil can be generated annually.

Picture from:http://www.oilgae.com/

Advantages:

1.Reduces carbon emissions    2. algae can be grown or cultivated anywhere