CPU: Gigahertz aren’t everything

It’s a very common misconception that clock speed is the indicator of how fast a processor is. Clock speed is expressed these days in Gigahertz (GHz), and in generic terms refers to the number of cycles per second a processor will process.

Now, that sounds like more is better. If you’re comparing two processors in the same family, that’s true, more is better. ┬áBack to one of our car analogies, if you look at a given car with its 4 cylinder engine and then compare it to the exact same car but with a 6 cylinder engine, clearly the 6 is better and faster. Now compare it with the same car running four cylinders in a boxer configuration with a turbo. Now which is better? The boxer turbo actually delivers far more power than a straight 6, despite being smaller. Why? Because it behaves differently, the turbo changes the overall energy extraction from the same given fuel.

The same is true of processors. In the early days of the Pentium 4, Intels main competition was the AMD Thunderbird processors. At that time, there was great debate about which was better, and Intel supporters held the Pentium 4’s far higher clock rate up as the definitive measure. During this heated war, serious benchmarking tools came about that have since been the ‘correct’ way to compare processors – actually testing them with real world use.

Not to anyones surprise within the retail side of this industry, AMD processors utterly blew away the Intel processors on a bang for buck scale in many scenarios. This led to a lot of shops offering both sides of the coin with explanations, and basically if you wanted a gaming rig you put in the AMD, if you had an office machine you went Intel. Well, if you listened to me when I was selling them anyway.

This is still largely the case, depending on the budget you’re working to. According to one particular benchmarking tool today, the Intel Core i7-3930K 3.2GHz is the top dog in processing power, retailing at $567.27US. The best performing AMD is the Eight Core FX-8350 4GHz which scored roughly 75% as well, but at $194.66US is only one third of the price. It’s a great example though of where the 3.2GHz is significantly better than the faster 4GHz

Personally I tend to recommend the AMD FX processors unless you want the absolute best and are willing to pay for it.

At the end of the day, if you want to make that decision yourself you need to look at actual benchmarking results and be clear on your own priorities. Often some processors will excel in the video rendering but perform poorly in single threaded tasks (basic office applications). You really need to do your research, or trust an expert! Just saying ;)