Computer Memory

Lesson Content

Inquire: Computer Memory – It’s Not What You Think


When we think of memory, we consider it from a human perspective. However, computer memory is a different thing entirely. Once you fully understand it for what it is, you’ll appreciate the fact that computer memory is actually a commodity.


Big Question

If computer memory isn’t about storage, what is it exactly?

Watch: Memory: The Real Horsepower in Your Computer’s Performance

Read: The Hardware of Memory


When you think of computer memory, you must first realize that it is a form of computer hardware. In other words, regardless of the type of memory under discussion, what we’re really talking about are silicon microchips with embedded circuits that allow for what is termed immediate memory.

DecorativeThe BIOS is a form of memory called by various names: non-volatile memory, primary memory, and firmware memory. The BIOS is referred to as non-volatile memory because it is always connected to a battery supplying constant power. The BIOS contains the initial boot-up commands that get your computer started before the operating system (OS) loads and takes over the processes of the computer. The instructions written into the BIOS are hard-coded into the chip, which means that once the commands are imprinted, they can’t be altered.

Since the early 1970s, there have been, however, forms of non-volatile ROM (Read-Only Memory) chips that are rewritable. These come in the forms of Erasable Programmable Read-Only Memory (EPROM – spoken “E Prom”) and Electrically Erasable Programmable Read-Only Memory (EEPROM – spoken “Double E Prom”). These allow for the instructions to be erased and new instructions to be blown in. However, there are limitations: the erasure and rewriting processes are slow, require specialized equipment, and can be done very few times before the chips are no longer able to perform. Another form of EEPROM is so-called flash memory. Flash memory, developed in the mid-1980s, can be erased and overwritten literally thousands of times. The limiting factor with flash memory is the cost per chip — which is substantially higher than other, less flexible types of ROM.

Random Access Memory

Volatile memory is typically referred to as RAM — Random Access Memory. This form of memory is only powered when the computer is running. When the power is turned off, or goes out by way of a blackout, anything running on your computer – meaning any files you have open, games you’re playing, or music you’re listening to – goes away without being saved. The trade-off for this volatility is that this form of memory is incredibly versatile; it is capable of storing data and programming code, in the form of programs, while it is running. In fact, when your computer is turned on, any programs in use, including the operating system itself, run from within RAM.

DecorativeMost computers afford the owner the opportunity to upgrade the RAM by purchasing more and physically adding it to the machine, which is a very simple process. How much RAM each person needs, and whether (or when) to upgrade the RAM, is a personal decision based on how the individual uses the computer. If you are a person who often has many software programs running, especially so-called memory hogs (meaning feature-rich programs that require a lot of RAM to run properly), you will likely notice that there comes a point when the software starts to slow down. Games, for instance, are often memory intensive by virtue of the amount of features they offer the player. When this point is reached, it’s time to consider upgrading the amount of RAM on your machine. Additional RAM is not terribly expensive, and the general increase in performance you receive in return for a RAM upgrade is generally worth the cost. When a system has adequate memory to run the programs routinely used, the software runs optimally, and you can run more of it than you might otherwise. This is why computers built specifically for gaming are typically heavy-laden with RAM.

Hard drives and USB drives represent other physical forms of memory found in and around computers. Hard drives (HDs) are mechanical drives; they contain a series of rewritable platters that spin within an airtight case. These platters contain all the data you store on the computer. The data is read from the platters by a series of read/write heads that move very quickly to either write data to the disks or read data from them. Because there are moving parts in the hard drive, they are mechanical in nature.

DecorativeAnother more recently developed form of hard drive is the SSD, or solid-state drive. This is a non-mechanical drive comprised entirely of silicon chips. Because there are no moving parts, SSDs are considered demonstrably faster and less susceptible to failure than HDs. The downside to SSDs is their cost. They are more expensive than regular mechanical hard drives, and they don’t, as of yet, have the larger capacities that hard drives have. As is often the case with the newest technologies, however, prices are slowly coming down, capacities are increasing, more new computers are shipping with SSDs, and more consumers are enjoying the improved speed and performance they offer.


Poll: If You Could Build Your Own…

Think about what you use your computer for.

If you had the opportunity to build a new machine for your intended purposes, balancing your needs with the costs of the system, about how much RAM do you think you would order? Hint: One way to find this out is to look at the memory requirements for your favorite software applications.

Expand: Where Might All of this Lead?


Because RAM stores both programming code – what we might call business rules – and data, it is being repurposed lately in very interesting ways. As you’re about to see, these new developments have important cultural implications for everyone on Earth.

Welcome to Big Data

DecorativeBig Data is terminology commonly used in business these days to characterize the amount of data that exceeds a business enterprise’s capacity to store, process, and/or analyze. Because so-called Big Data outstrips the capacity for storage, where does the data go?

Simple: it goes to the Cloud.

There are businesses that specialize in aggregating data and providing it to other businesses for analysis. Facebook is one such company. Now, imagine the sheer amount of data that Facebook sees from its users, every second of every minute of every day. It’s inconceivably large. It would not be quite impossible, but certainly far too expensive to attempt to store this data in one place. So, using what is becoming a prevalent model for large businesses, the data is outsourced. Meaning, it is stored in the Cloud.

Storing the data is one thing, but what exactly is it stored in? Again, the answer is simple: it is stored in data warehouses. A data warehouse is extremely powerful software that not only provides for the accurate archiving of data but, most importantly, contains incredibly powerful tools for analyzing the data. One such data warehouse is called Oracle.

Data warehouses offer analysis tools like predictive analytics. Predictive analysis explores large volumes of data for relationships and patterns and then makes surprisingly accurate conclusions about what will occur in the future. In essence, this tool enables businesses to very accurately predict the future! It’s because of this capability that Oracle got its name: an oracle is someone who can see the future.

For many years, this kind of analysis was somewhat time consuming. That is, until it was discovered that RAM can contain both programming (remember: business rules, meaning analysis) and data.

DecorativeNow, there are means by which the enormous amounts of data that arrive every second of every minute of every day can be analyzed in real-time (r-t). Businesses that rely on up-to-the-minute marketing – and there are a lot out there – now have the ability to watch trends as they are developing and guide them. This means that if you were to suddenly decide that red sneakers were cool, and you and thousands of your friends went out and bought them, somewhere, predictive analysis might detect that as a trend and begin marketing red sneakers to people in your age range.

All of this is possible due to advances in computer memory!

Lesson Resources

Lesson Toolbox

Additional Resources and Readings

Memory & Storage: Crash Course Computer Science #19 (Video 12:16)

A Crash Course video giving clear information on computer memory and storage

How Computer Memory Works

An article giving more information on the types of computer memory

Timeline of Computer History

An interactive timeline illustrating the history of computer memory development

Lesson Glossary


AJAX progress indicator
  • Big Data
    the amount of data that exceeds a business enterprise’s capacity to store, process, and/or analyze
  • BIOS
    Basic Input-Output System; a chip or chipset that contains the instructions needed to boot your computer once the power is turned on. The instructions are written to the BIOS as a part of read-only memory (ROM) and are not meant to be tampered with. The BIOS is powered by a battery so that the(...)
    Electrically Erasable Programmable Read-Only Memory; a further development of EPROM technology
    Erasable Programmable Read-Only Memory; a form of ROM that can be erased and overwritten a limited amount of times
  • miniaturization
    the trend to manufacture ever smaller mechanical, optical, and electronic products and devices
  • RAM
    Random Access Memory; also known as “volatile” memory; form of memory only powered when the computer is running
  • ROM
    Read-Only Memory; also known as “non-volatile” memory for the fact that the chipset is connected to a battery allowing your computer to boot-up when the power is turned on

License and Citations

Content License

Lesson Content:

Authored and curated by John Kormos for The TEL Library. CC BY NC SA

Media Sources

DecorativeTech Ram Gpu Technology ComputerRecklessstudiosPixabayPublic Domain
DecorativeComputer Memory ChipsPetr KratochvilPublic Domain PicturesPublic Domain
DecorativeDesk Computer Business OfficekulinettoPixabayPublic Domain
DecorativeSamsung 840 EVO SSD-1Samsung BelgiumWikimedia CommonsCC 2.0
DecorativeAnalytics Information InnovationxreschPixabayPublic Domain
DecorativeSneaker Shoe Foot FootwearMabelAmberPixabayPublic Domain

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