PC Building, P5 - Data Storage

Deciding on the two most important parts of the PC (the processor and the motherboard) gave me the framework I needed for selecting the other essential pieces. Next I decided to tackle data storage: namely the memory (RAM) and hard drive.

RAM (random access memory) is the computer's main storage device for temporary data. The processor (CPU) uses RAM as the place to store data it uses to run programs. RAM data storage is temporary because data on a memory cell is based on the electrical charge or state of its components, which is lost when the computer loses power. RAM functions the same as CPU cache memory discussed in P3 of this series, except that it is cheaper to build but slower performing (this is the difference between "static" and "dynamic" RAM, which you can read more about here).

When selecting RAM, the type, speed, and size of each module (stick) need to be considered. Above all, the RAM must be compatible with the system, meaning the motherboard must have support for the type and speed of RAM being used, and also have the number of slots and the memory capacity desired.

RAM type and speed can get fairly involved. To keep it simple, the standard RAM used in computer building is the DDR series (of which DDR3 is the most widely used today). Compared to DDR2, DDR3 RAM consumes less power and can run at increased data speeds. The speed of RAM (measured in MHz) determines how fast and how efficiently it can receive and transmit data to the processor.

Capacity is more straightforward. Capacity of a RAM module is measured in megabytes (MB) or gigabytes(GB), and it describes the actual amount of storage space available. Programs and operating systems require a certain amount of available memory (capacity) to run, below which system performance will suffer and applications will run sluggishly or not at all. More RAM capacity allows for more multi-tasking of memory intensive programs. Total capacity is the combined capacity of all the modules in use, and the number of motherboard RAM slots available determines how many modules can be used.

Whew! Ok… so a lot to take in regarding RAM. But for all that info, most people (myself included) will do fine following the market standard, which currently is DDR3-1600MHz. I now have two 4GB sticks in my possession, for a total capacity of 8GB.

Aight… now on to hard drives!

Hard drives are direct-access storage media (like a tape, CD, or DVD), meaning data is permanently written, stored, and accessed. Unlike memory, hard drives can store your data when the power is off. This is where all the operating system data, your word documents, and your photos is stored.

There are three types of storage drives on the market today: regular hard disk drives (HDDs), solid state drives (SSDs), and hybrid drives.

HDDs house metal disks with magnetic coatings that contain the data. Read/write arms access the data by spinning the disk. Hard disk drives are the least expensive in terms of capacity/$ (Yay!), but are also the slowest (Boo!). HDD speed is solely based on the speed the internal disk spins, measured in rpm. The standard HDD speed on the market today is 7200rpm.

On the other end we have solid state drives. In SSDs all data is contained on a series of interconnected flash memory chips. Because of this construction, read/write times on SSDs are significantly faster than HDDs. In addition to speed, SSDs contain no moving parts, and thus are less fragile and more reliable than HDDs.

Hybrid drives are HDDs that have a small SSD built in (usually 1-10% of the total storage size). This SSD space is used as a cache for frequently used files for increased performance over a normal HDD. A hybrid is the happy medium between the speed of an SSD and the lower cost and storage capacity of an HDD.

I ended up choosing a 250GB SSD for my storage needs. SSDs provide a performance boost over regular drives or a hybrid drives that can't be overlooked, and for me was worth the added cost. In the future, I will likely add an HDD as a secondary drive for additional storage space.

So my system is well on its way to completion. In the next post I will tackle the last few big pieces of my build: the power supply and graphics card.

Sources

Hard drive Image - Geekyhabitat.com - Choosing a Hard Drive

RAM Image -Easy-computer-tech.com - Memory

PCMag.com - HDD vs. SSD