Tech Explained: File Memory and Data Usage

    A Hard Disk Drive, or HDD, is a means for computers to organize and store files.  It works by use of magnetic systems that utilize rotating platters coated with magnetic material (Arpaci-Dusseau & Remzi H. & Andrea C., 2014, para. 6).  These rotating platters store data that is written upon it via a moving actuator arm which has a paired magnet (Arpaci-Dusseau & Remzi H. & Andrea C., 2014, para. 6).  Once data is imprinted onto a HDD, it can remain there even if the power is shut off.  However, if the HDD is damaged or the data is corrupted, the data within may be irretrievable or intensely difficult to retrieve.  This is why back-up files are important.  

    You can back-up, or make copies of, your files on various external devices and services.  For instance, a cloud service like One Drive, or a hardware device like an external hard drive.  Once copied on these devices, it will exist there if you need it.  An example of needing it is if your computer’s power supply short circuits, and “fries” your motherboard.  Once that happens, all bets are off if your computer’s other components were similarly damaged.  If your hard drive takes the hit, then you would lose all files on it.  However, if you had backed it up on, say, One Drive, you could then collect all of your files again on a new Hard Drive.  You would resume as if nothing had happened.  

    The main challenge of this is keeping diligent on making regular copies of your back-ups, and diversifying your efforts.  In the past I have forgotten to back-up my files regularly, and so when I went to restore them I was forced to restore a much older state of my computer.  I lost many months of data.  Similarly, I’ve backed up files on disc only to later find out that the disc’s content is corrupted.  I should have backed it up on other means (at the time, cloud software didn’t exist.  However, I could have used an external HDD).  My current back-up plan is two-fold.  I keep my computer connected to One Drive, which automatically backs my files up daily.  Secondly, I periodically back-up my most important files to an external hard drive.  In this way I have redundancy, and I am ensuring my back-up files are up to date.

    RAM, by contrast, holds data temporarily.  Where as when a HDD keeps the data even when powered off, RAM loses the data when it loses power.  RAMs purpose is to act as an in-between with the CPU and the HDD.  It stores data instructions, or a recipe of how to use the data, temporarily from the HDD, which the CPU then uses to load into faster.  It is much quicker for the CPU to utilize the data when it reads it from the RAM. 

    I currently have 16 GB of RAM installed on my computer.  Right now my usage is 9.2 GB, with a multitude of tabs open on my internet browser, and various other applications running in the background.  I experience no lag or latency when opening or closing my documents right now, and can freely browse the internet with my browser.  However, if I were to open a video game up right now I would find that my RAM gets much closer to 16GB of usage, and my performance in the video game is degraded.  If I had more RAM, for instance 32 GB, I could also run my video games with no drop in performance.  If I had less RAM, I might have trouble writing this document right now and may need to close my internet browser to save on memory usage.

 

References

Arpaci-Dusseau, Remzi H., Andrea C. (2014). Operating Systems: Three Easy Pieces, Chapter: Hard Disk Drives. Arpaci-Dussaeu Books. https://pages.cs.wisc.edu/~remzi/OSTEP/file-disks.pdf