Short for Random Access Memory, RAM is a type of memory in which any byte can be accessed without having to go through the previous bytes (hence the random access in the name). If you want, imagine a box of toys arranged in one horizontal layer which you can access from above. You can simply reach and grab the one you want, but if your access route was through some kind of a door on one of the sides, you would have had to touch all the toys in your path to get the one that you wanted.
For lack of better terms, the RAM or, simply put, the memory is the part where your computer opens the software which you are currently running. Once you close a program, it will be deleted from the RAM to make room for new ones. The number of applications you can run simultaneously is directly related to the amount of RAM you have installed.
The different types of RAM memory: SDRAM, DDR1, DDR2, DDR3 and (soon to come) DDR4 differ not only by their technical specifications but also physically. This means that you will not be able to place a RAM pad into a slot designed for a different type of memory.
Although they have a lot less technical specifications then most other components in your computer, these specs are probably still hard to understand for the less hardware-savvy people, so I will try to explain them in terms that are easier to grasp.
- Number of pins is a pretty much self descriptive term. Each RAM pad has a number of pins which has to match what is written on your motherboard. As an example, 240 pins are generally designed for desktop motherboards while 200 (204) are made for laptops.
- Memory is a number measured in GB which expresses the capacity of the respective RAM pad. Although it may seem that way, this specification isn't directly related to how fast your computer will run, but to the number programs you can run at once. (This description is a little loose as some applications take up more RAM space than others, but hopefully you will understand what I mean).
- Just like in CPUs, the clock speed (frequency) defines the rate at which the RAM pad processes its data. This number is directly related to the speed with which your computer will perform its actions. It is generally measured in MHz and, in order to obtain maximum performance, you should make sure that your motherboard offers support for the maximum clock speed which your RAM can achieve.
- The Bandwidth tells you the actual speed at which your RAM operates. Simply put, it is a formula which calculates the MB/s with which your RAM can read and copy. Let's say you have DDR1 with a clock speed of 400. Your bandwidth will be as it follows: 400 x 8 bytes x 2 (DDR means Double Data Rate) = 6,400 MB/s.
- Voltage represents the power consumption of your RAM. And just like with household appliances, newer memory pads have smaller consumption level, thus save you money on the electric bills.
In case you want to buy RAM, the best brands in my experience are Kingston, Corsair, Micron, Samsung and Mushkin. It's not a particular order, just the way I remembered them, off the top of my head.
The power supply unit (PSU) is more important than most people believe. Not only do you need to make sure that all the components inside (and outside) of your computer's case have enough electrical power to run in optimum conditions, but you should also make sure that the PSU offers the necessary protection to your hardware.
Nowadays, calculating how much power your computer will need is pretty easy: you can either install specialized software such as PSUCalc or simply use an online calculator such as eXtreme calculator or PSC and match the results you get with the specifications on the power supply that you are buying.
The electrical current in the outlet is not always perfectly stable, and unless you are using a UPS (Uninterruptible Power Supply), your power supply unit along with some of your hardware might get fried by an unexpected fluctuation. These are the minimum protections your PSU should offer:
- UVP - under voltage protection;
- OVP - over voltage protection;
- OCP - over current protection;
- OTP - over temperature protection;
- OPP - over power protection;
- SCP (optional, but I recommend it) - short circuit protection.
As far as brands go, Corsair is the best one on the market in my experience. Other options include Coolermaster and Thermaltake.
When it comes to coolers, things are a bit less complicated, and you don't need to worry too much about brands and technical specifications. What I learned from experience is that no matter how many coolers your components have, you will most likely still need something in addition. For example, my graphical card came with three encased coolers, the CPU had a cooler and the PSU had a cooler, but the temperature inside my case was still pretty high. So I installed 5 additional ones (two on the front side, two on the top and a large one on the left side) to keep things under control.
The way the cooling system works is like this: some of the coolers will direct cold air into a specific hardware component, while the others will evacuate the hot air out of your case. You need to create a current inside your case in order to get satisfying results. The easiest way to get appropriate cooling is to install a few case fans and upgrade the fan on your CPU. (If you buy a case with specific slots for multiple fans, things will run even smoother.)
I hope this helped, and once again, if I missed anything or you have any questions, please post them in the comments sections, and I will try to address as many as I can in the final chapter of this guide.