Computer Random Access Memory (RAM)

Computer random access memory

Computers tow have many hardware components. Among them is the RAM. A computer random access memory (RAM) is very important component and they play and important part in determining the performance and speed of your PC

What is RAM

You already have interacted with Computer random access memory(RAM) or may have used one on your pc or your smartphone. In full RAM stands for Random Access Memory. RAM is a type of computer memory that stores data temporarily when your computer or your phone is powered on. Once there is no power or the device is turned off, all the data is lost. They are solid-state memory. If you do not know what is solid-state memory, it is a type of memory device that does not have any moving parts at all.

Computer random access memory
Two random access memory (RAM) sticks

Other names used to refer to RAM are main memory, primary memory, or system memory. RAM is faster than other types of storage such as CD, or hard drive. I know you wish to why. The reason why RAM is faster than other storage devices is that the data store in the RAM is accessed randomly instead of sequentially. However, RAM is volatile memory meaning once the power is disconnected from the device you are using all data is lost.

Unlike a hard disk drive, RAM is very fast memory. The speed and performance of your PC or phone are directly proportional to the size of RAM you have installed. You may have realized that if your computer little memory size, it becomes sluggish or too slow. However, this does not mean you install too much RAM on your PC. The amount of RAM you need should be determined by what you need to use your pc for. For instance, video editing requires a large amount of RAM, at least 8Gb RAM should do.

History of RAM

The first random-access memory was introduced in the year 1947 which was typically a Williams tube. This tube was typically a cathode ray tube (CRT). The data was store as electrically charged spots on the face.

Then enter the RAM.  It was a magnetic-core memory invented in the same year as the William tube. It was invented by Frederick Viehe who filed several patents. This type of memory used ring wire to store data. One bit of data was stored on each ring.

You are probably asking, and when did the types of RAM that we use today get invented?  In the year 1968, solid-state memory was invented in the year 1968.  This type of memory uses transistors to store data. It is was a dynamic Random access memory.

Why more memory helps.

Everything you do on your computer relies on computer memory. This includes moving your mouse around, though it uses a little amount of your RAM. Since you might be among those who prefer to use your pc for multi-tasking, you probably need RAM.

The current operating systems require constant updates that run in the background. Antivirus and operating systems use most of your RAM. In other words, the things that you are doing with your PC, the more RAM you need.

Note: if you are to chose between one 8Gb RAM stick and two 4 Gb RAM sticks, go for two 4 Gb RAM sticks.

Types of RAM

All computer random access memory (RAM) can be RAM can be broadly classified SIMM and DIMM. The two categories describes how data is transfer. DIMM is 64-bits memory while SIMM is 32-bit memory. DIMM can further be categorized into into static RAM and Dynamic RAM.


DRAM is a type of RAM that is commonly used today. You will find one on your computer, phone, or laptop. This type of RAM allows high data densities at a relatively lower cost.

How DRAM works

DRAM was invented by IBM. The major components used for storage are capacitors and transistors. Since the data is stored either as a 1 or a 0, the transistor is used to charge or discharge the capacitor. In the discharged state, the capacitor represents zero while when charged, the capacitor represents a logic 1.

When the data is being written on DRAM, a bit line is used. So, charging and discharging a capacitor is done by the bit line (also known as a word line). The bit line goes high which causes the transistors to connect to capacitors and the value (0 or1) is either written or retrieved from the capacitor.

The disadvantage of this type of memory that capacitor charges leak after some time.  This is why this type of RAM requires constant refreshing. In fact, the name was a moniker for the reason that the cells have to refresh dynamically.

Static RAM (SRAM)

Static Random-Access Memory uses latching circuitry (flip flop) instead of transistors and capacitors for data storage. However static RAM is also a volatile memory just like the DRAM.  The other difference between SRAM and DRAM is that the former is faster and more expensive than the latter. You will be fascinated to learn that static RAM is used for CPU cache. Another common use of SRAM the digital-to-analog converter on a video card.

How SRAM works

In each memory cell of SRAM, there are four transistors that are placed as two cross-coupled inverters. This transistor configuration has two stables states that are equivalent to a 0 or a 1. In addition to the four transistors, there are two more transistors that are used to control the read and write operation of each cell. This is why SRAM memory cells are referred to as 6T cells.  It is possible to have 8T or 10T if more transistors per cell are used.

SRAM requires three switch devices to work. Though there are many types of 3 switch devices, CMOS technology is used. This technology ensures only a little power is consumed.

You will be surprised to know that this memory storage works in quite a straightforward manner. When a cell is selected for writing, the value is stored in the cross-coupled flip flop. It is possible to address each cell individually since they are arranged in a matrix.

Just like it is with the DRAM, you will be fascinated to know that each cell is accessed using a word line. Bit line controls the two access transistors which determine whether the cell ought to be connected to the word line or not.

Further categories of RAM

You may have noted that over time computers are becoming better in terms of speed, reliability, size of storage among other things. Well, this is due to the evolution of hardware as well as software. RAM being part of computer hardware has evolved over time. Today, you can find a lot of RAM variations in the market. Some of these variations are DIMM, RIMM, SIMM, SO-DIMM, and SOO-RIMM.


SIMM is an acronym for a single inline memory module. They are 32-bit memory that worked very well with an Intel Pentium processor.  However, when the 64-bit processors emerged in the market, it was necessary to install two SIMM at a time to operate well. To address this limitation, the DIMM RAM was introduced into the market. There is a DRAM that falls in this category. They are out of the market today that is why may not be possible to find one even on amazon.


DIMM is an acronym for a dual in-line memory module.  It is a 64-bit RAM that was natively made for fast data transfer. DIMM is an upgrade of SIMM that only used a 32-bits data transfer protocol. DIMM is DRAM is nature. It is important that you do not confuse this category with  Double data rate RAM (DDR RAM). However, the latter is an umbrella name for RAM while the latter is a subcategory under the DIMM.


The RIMM is more expensive and slower than DIMM. RIMM stands for Rambus in-line memory module.