Microprocessor Buying Guide - Which Microprocessor should you buy in your new system ?
IS IT HYPERTHREADED? Hyperthreading is a way of making one processor (or core) act like two. When a processor is working on a task often parts of it are dormant. Hyperthreading is an Intel technology that allows one processor to harness its inactive transistors and make it work like a second processor. So if a processor is hyperthreaded (or has the HT designation), it’s just one chip that has been configured to work like two.
WHAT’S THE CLOCK SPEED? Every chip has a clockspeed rating. Basically this is the speed at which is executes instructions. This is measured by either megahertz (MHz) in older computers such as the Pentium III or gigahertz (GHz) on newer computers (1 GHz = 1,000 MHz). This used to be a good indication of how fast a computer worked, however it’s no longer a reliable indicator. A computer with an Intel Core Duo 2 chip that runs at 2.93 GHz will out-perform a 3.6 GHz Pentium 4 HT system.
SINGLE or DOUBLE CORE? Processors come in single or double varieties. Until the Pentium 4 came along, a microprocessor meant there was one workhorse inside the chip. Then multi-core processors came along.
Most popular today are dual-core chips. They are not specific to a particular model or maker. As the name implies, they contain two separate processors on one chip. Intel’s Core 2 Duo (and the new Core 2 Extreme) and AMD’s Athlon X2 Dual-Core models can handle several tasks at the same time without having to slow down.
While one processor core is writing a video to a DVD for example, the other one can be managing word processing, photo editing or web surfing.
Though many older programs do not take advantage of dual-core technology by themselves, they are still faster in a dual core system, especially when used with a smart operating system like Windows XP. It knows enough to send one application to one side of a dual -core CPU, and a second application to the other. Another feature these new processors offer is that they are energy-efficient, since two cores on one chip draw less electricity than a single CPU needs to process one computing task one after another. This is especially important in laptops that need to preserve every little bit of battery life.
And one more tip: In the Intel world, look for a processor number. The higher the number the faster the chip performs. For example the Intel Pentium D Processor has a processor number of 915 while the Pentium Processor Extreme Edition has a processor number of 965. So the latter outperforms the former. Since AMD does not subscribe to this indicator it’s not helpful to use this metric to compare processors across brands.
Sample Chapter from Computer Buying Guide.