The Anatomy of a Computer

All computers share some essential components, whether a laptop, desktop, or Mac. These parts have stayed fundamentally the same since the earliest personal machines, like the Kenbak-1 back in the '70s (but that’s a story for another day). The basic parts of a computer are:

The Power Supply Unit (PSU)

The unsung hero of your computer system, the humble power supply, is the system's most fundamental component, but nothing would happen without it.  The PSU takes the Alternating Current from the plug in your wall and converts it into Direct Current that your computer can use. It also transforms the 230 volts (120 volts if you’re in the US) from the mains into much more reasonable amounts (12 volts, 5 volts, and 3.3 volts).  This is critical as the components in your system are very delicate (in fact, you can easily destroy one by exposing it to static electricity).

Power supplies are rated in Watts and come in sizes from 350 to 1000 watts. The bigger the PSU, the more components you can plug into it. Under-specifying the power supply can lead to serious issues, and using one larger than you currently need is always best. 

If you have problems with the PSU, you can expect strange error messages, and issues arising from a faulty PSU can be notoriously tricky to diagnose.

The Central Processing Unit (CPU)

Often referred to as the ‘Brain of your computer’, the CPU is a chip that is very good at solving math problems very, very quickly. Even the slowest, least powerful CPU can process millions of calculations per second.

When you boil it down, computer programs are nothing more than long lists of instructions that must be processed and done quickly and in the correct order. It’s the processor's job to, well, process these instructions.

Physically, a CPU is a wafer of silicon with hundreds of pins, or hundreds of tiny sockets set into it.  Processors are very tricky to work with and very fragile.  CPUs are extremely sensitive to heat; the harder you work them, the hotter they get.  It is possible to squeeze more speed out of a CPU by ‘overclocking’ it.  This can result in a slightly faster system if done right, or can kill your system if done incorrectly.

Issues with the CPU can include the dreaded Blue Screen of Death and frequent system stalls or reboots.

Random Access Memory (RAM)

RAM is one of the components that dictates the ‘speed’ of your computer. The more RAM you have and the faster it is, the faster your computer system will be. That said, it is possible to have ‘too much’ RAM. Beyond a certain point, adding more RAM won’t make a noticeable difference unless you’re doing high-end tasks like video editing or running virtual machines. This won’t threaten the system's integrity but will be a waste of money.

Random Access Memory is Random because it can access any memory address (location in memory) at any time without going through the whole file to get to the section of the file or program that you need.

When your system needs to access a file or program, it makes a copy of the program and loads it into memory.

The most common type of RAM is long, narrow silicon wafers with a number of chips soldered to them; this package is known as Dynamic RAM. It is called dynamic because it must have power running to it to retain data.

Motherboard

The motherboard, sometimes called the ‘main board’, is the most significant component in the computer and is a large circuit board that all the other components plug into. In many ways, it can be considered your computer's central nervous system. 

These days, the motherboard will normally have several components soldered on; these normally include the wherewithal to facilitate sound and networking, but some higher-end models also include high-definition graphics and other facilities.

Also built into the mainboard, you will find ports that the keyboard and mouse plug into.

You will also find slots for expanding your system's capacities, such as upgrading the video card (graphics capability) or adding high-definition sound.

Hard Disk

Your computer's long-term memory. Two kinds of devices serve the purpose of storing files for prolonged periods: HDD and SSD

HDD are older technology now and have started to be phased out of newer high-end systems.  A Hard Disk Drive is several physical spinning disks that have phenomenal storage capacity but are limited by the physical capabilities of the disk spinning in terms of access (or more specifically, read/write speeds)

SSDs are similar to extremely high-capacity thumb drives. They are made of chips that rapidly and silently access information.

One common issue with HDDs is that they don’t save information in one long, unbroken string of data. Instead, they save information across the whole disk, leading to slowed read/write speeds as these bits of a file become fragmented. Running a defragmentation tool at least once a month is essential to keep your system in good order.

Optical Drives

Recent trends mean that optical drives are much less common. Optical drives are CD or DVD drives integrated into a PC's case. 

It’s a fairly common upgrade to put a DVD player in a personal computer or sometimes a CD Rewriter for archiving and backing up files.  The upgrade process is relatively straightforward, and as long as the PSU can handle the load, it should function without issue.

Problems with the optical drive can be caused by old or corrupted drivers (small programs that make the system recognise a device)

So, there you have it, my friends, my whistlestop tour of the inside of a PC. If all this has whetted your appetite and you want to upgrade, go ahead and drop me a line. If there is a mysterious device you can’t identify, sound off in the comments. I’d love to hear from you.