“Gigabytes, Gigahertz? What is this stuff?” (Part 1)

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Comments   |   Computer General, Hardware

So, you’re shopping for a new computer, eh? Well, prepare to be inundated with giga-this and giga-that; it’s part of it. You wouldn’t buy a car without knowing how much horsepower it has, would you? Whether it is automatic or manual transmission would be important too. Most people would also be interested to know whether it is front-wheel drive or rear-wheel drive also. The same goes with computers: You want to know what it is that you are getting before you buy it. I have these same conversations with people pretty much ever day at Computer Depot, so I thought I would share them with the class! What follows is a simple, down-to-earth, explanation of the giga-who’s and giga-what’s you’ll encounter while shopping for a computer.

Warning: What follows may seem like a lot of information; so sit down, take a breath, and read slowly. It can seem a bit overwhelming at first, which is why I will be doing a series of posts on this topic rather than trying to fit everything into one.

CPU Clock Speed (Measured in gigahertz or “GHz”)

The terms “processor” and “CPU” are interchangeable terms. The CPU is the “heart” of the PC. Just so you know, I’m not talking about the tower. Many people think the tower is called the CPU. This is not true. The CPU is the central component within the tower. In a sense, the CPU is the computer. Everything else inside the tower is an accessory to it. The clock speed of the CPU used to be an extremely important number. Normally, one would think the higher the number, the better. Technically, that is still true; but it is probably the most unimportant number on the list of specifications in most situations. Unless you are an avid, savvy, or just plain obsessive computer user such as myself, there is little point in allowing this value to be a deal-maker or deal-breaker. With the leaps in CPU technology that have taken place over the course of the past decade, the clock speed of the CPU is far less important than it used to be. It is still nice to know, but what is much more important is…

CPU Brand

This is far more important than the clock speed and requires a bit more explanation. Mind you, it will probably take a little bit of research and/or question-asking to make sure you get the right processor for you. Clock speed would be far easier to understand (The higher the number, the better!), but this is the important part.

Generally, “Intel” processors are going to make for more expensive computers, and they typically cater to the business side of the consumer market. It is not my personal opinion that Intel makes better processors, although some may hold to that thought. Intel has been around longer, but their competitor “AMD” (Again, my opinion here) makes just as good a processor in many cases for 1/2-3/4 the price. AMD computers will carry a lower price tag and typically cater to the gaming/enthusiast line of the consumer market. Obviously, there are gamers that prefer Intel just as there are business users that prefer AMD; I am simply generalizing.

CPU Type and Model

After the brand name, you will see the model number of the processor. Consumer-line Intel processors are going to be called, “Celeron,” (Never buy a Celeron PC! Trust me on this.) “Atom,” “Dual-Core,” “Quad-Core,” “Core i3,” “Core i5,” or “Core i7.” These are listed in ascending order of power. Meaning, the closer to the end of the list, the more powerful the processor.

Consumer-line AMD processors are going to be called, “E-***,” (where the *’s are numbers) “Sempron,” “Athlon” (Or “Athlon II”), or “Phenom” (Or “Phenom II”), in the same ascending order. AMD processors may also include a multiplier value at the end, which is the number of “cores” built into the processor. X2 means it is dual-core. X4 means it is quad-core. X6 means it is six-core.

So what is a core?

This begs the question, “What is a core?” Cores are like miniature processors built into the main processor, and make up a large part of the reason why the overall clock speed of the computer is so unimportant now. Multiple processors mean multiple streams of information.

Allow me to explain. Imagine a busy highway. Having multiple cores is like having multiple lanes as part of one highway. Country roads with only one lane per direction can be thought of as a single-core. The Interstate would typically be “dual-core” (two lanes) while busier, metropolitan areas of the Interstate may have as many as four (quad-core) or six (6-core) lanes. Generally, a single-core processor can only process one calculation at a time, while a multiple-core system will be able to process more calculations at once.

Years ago, when there was no such thing as a multiple-core system, the clock speed was very important. It meant that the one calculation at a time could be performed faster in a 3.4 GHz computer than in a 2.0 GHz. However, once you injected so much power into a processor that it got to the 3.6 or 3.7 GHz range, you would lose so much energy to heat that you would not see a difference in performance. Efficiency became a problem. So, developers moved to hyper-threading, which was the beginning of the movement to multiple cores. With multiple cores, you can get more work done, faster, while using less energy. In other words, a 1.8 GHz dual-core processor will perform faster and more efficiently than an old 2.8 GHz single-core.

There are other specifications to processors (cache, bus speed, etc.), but I think we have gone far enough into the discussion for our purposes in this blog.

Next week, we’ll talk about RAM or memory, what it does, and why it is important. I hope this series of posts will be helpful.

Au revoir,

Scott Davis
Store Manager and Lead Technician
Powell Location

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