The CPU The processor or CPU is the equivalent to the brain. Everything, every peripheral, every component is connected to the CPU. The ancient Romans said that “All roads leads to Rome”, well in a computer everything leads to the Processor. A simple click of a Mouse button goes first through the Operating System, which translates the action into machine code for the Processor and then an action is executed according to the input (mouse click). Very simple Action-Reaction interrelationship between all components and peripherals with the Processor at the center. As you might know there are two main manufacturer of CPUs for x86 type of computers, Intel and AMD. The x86 designation refers to the instruction set. The instruction set is just a list of instructions that a Processor can execute. x86 Processors shares the same instruction set. Windows Vista is made to work only with x86 Processors. All the software (including the OS) that you use must be made for that Processor, otherwise it won't work in the same way a diesel engine won't run on gas. Intel is the original developer of the x86 instruction set and have ever since been the leader, although AMD has made serious inroads the past few years. Intel is still the undisputed leader and your choice should be Intel first and only AMD if it makes sense financially. An AMD processor could also be a good choice if you want to run a 64 bit Linux OS like Ubuntu 64bit, because of the abundance of cheap 64 bit AMD Athlon Processors on the market. How to choose a CPUThis can be tricky if you don't know what to emphazise in your system. I will give you a few tips that can help you decide. First, there is very little gain in going from a 2.5 GHz to a 2.66 GHz Processor. Steps of 0.5 GHz (e.g. from 2.5 GHz to 3.0 GHz) will make a visible difference in performance. Second, you should be able to spend as much money on your Motherboard as on your Processor. If you want a Processor that costs US$ 150, then spend at least that much on the Motherboard as well. If you can, double the amount you spend on the Motherboard compared to the Processor. Remember, the Motherboard gives you more bang for the buck than the Processor. Also always go with the Retail CPU, not the OEM. The Retail version includes a Heatsink/Cooling and comes with a 3 year warranty, which the OEM doesn't.TechnicalsThere are several factors you need to consider when buying a Processor. There are a lot of technical information regarding the Processor that you should understand. I will not mention here technologies like Hyper-threading, because they are of the type that pop up for a few years and then something new is marketed and nobody cares anymore. I will instead focus on that which is important and will stay the same for many years to come.Clock Speed: For the average computer buyer, this is the one piece that enjoys the most attention. This is unfortunate, because the Bus Speed, Core Type and especially Cache Memory are very important to the overall performance of the CPU. Do not choose a Processor solely on the Clock Speed, but look at the Processor as a whole. The Clock Speed can also be changed by the user on most Processors. This is referred to as Underclocking and Overclocking. Bus Speed (FSB): This is the speed of which the Processor is connected to the chipset on the Motherboard. The faster the better. Core Type: This is probably the least regarded part that have a significant impact on the performance. Take two top-of-the-line Processors from Intel, the Core 2 Extreme X6850 and Core 2 Extreme X9650. Both have the same Clock Speed, the same Bus Speed and the same number of cores, but the X6850 is based on the Kentsfield XE core while the X9650 is based on the Yorkfield XE core. The Yorkfield XE core uses 45nm technology while Kentsfield XE uses the older 65 nm. The Yorkfield XE core is superior to the Kentsfield XE and thus provides a performance increase. However, don't do the mistake and look only at the Core Type, the Processor as a whole is the most important. Number of Cores: Now that more and more software is made for multi-core Processors, the more it makes sense to buy one and most Processors offered are now multi-core. Intel and AMD do not use the same technology to achieve multi-core Processors. The AMD design is more of a true multi-core design, but the question is if it is better. Cache Memory: Also referred to as the L2 cache and it is the memory that is directly attached to the CPU. The size of the L2 cache has quite a large impact on the performance of a CPU and thus the whole computer. In general a Intel CPU has more L2 Cache and therefore will be more expensive than an AMD rated at the same Clock Speed. Remember that we have three types of memory in a computer, the Motherboard (slowest), RAM and L2 (fastest). The L2 is much faster (shorter distance to the CPU) than RAM and can make a rather large impact on computational intensive applications like gaming, video editing or machine learning. Bit Width: This is actually a quite complex subject. The only thing you have to know is that a 64 bit Operating System needs a 64 bit Processor. However, a 32 bit OS and applications can be run on a 64 bit Processor. Most software today are 32 bit which means they can run on a 64 bit Processor but doesn't take full advantage of the processor. Only pay attention the Bit Width if you are into running 64 bit OS and applications and want to take full advantage of the Processor. Wattage: Since more and more users are requesting energy-saving computers, the Wattage rating becomes more important. A high performance CPU will have a Wattage of 120W to 150W, which is quite much if you have no need for it. For example AMD have released CPUs with 45W and 65W rating for those of us that want to save energy and this trend is going to continue. If high performance is not absolutely necessary then choose a lower Wattage Processor, saving the planet and your pocket.
|
Except for Intel and AMD there are one other manufacturer, VIA (Nano, C7 etc). However, you will only encounter VIA Processors in specialty applications (e.g. UPC). Some mini-ITX boards feature the VIA Processors. VIA offer Processors with very low power consumption (think 5W to 25W) and thus lower performance. Excellent choice for e.g. a car computer project where low power consumption and small size is most important.
Socket Type: With every new Processor generation Intel and AMD introduces a new Socket to take better advantage of the new technology. Obviously an Intel Processor doesn't fit in an AMD Socket. However, a old AMD Athlon with a 754 Socket will not fit in the newer AMD AM2 Socket. All Motherboards and Processors clearly state exactly which Socket that is supported. Just pay attention and double check before you buy and it will not cause any problems for you.