What is a processor?

The processor is most definatly  the most important components in a contemporary computer. The term processor, CPU and chip usually refer to the central processing unit. Every action and command your PC does depends on communication with the CPU so its performance is crucial to the overall computer experience.

There are hundereds of different processors available so it is plausible to not be certain about how the different models compare in enactment and which one is right for you.

Not that long ago comparing processors was typically quite  easy. A higher rated megahertz processor would make a faster PC, for example an 800MHz processor would make a faster PC than a 600MHz processor. As processor speeds have increased into the gigahertz (1000MHz is equivalent to 1GHz) range manufacturers have had to introduce unclear naming schemes. It is often harder to understand the naming scheme that Intel and AMD use than the technologies behind the processor!

Comparing processors is no longer about finding the highest speed processor possible in MHz or GHz. To get the best performance you need to take into account the whole specification of the processor including the number of cores it has, system bus speed and the amount of cache to work out its performance.

Here is a brief list of what the specifications mean:

Clock Speed: Usually listed in Mhz (Megahertz) or GHz (Gigahertz) this used to be the primary indicator of processor speed, although in recent years this has become less authoritative. Both Intel and AMD have invested huge amounts of money in developing their processors to maximise the output of each and every clock cycle and in doing so they have made the actual clock speed less important. A 1000MHz processor today is approximately 16% faster than the previous generation when you compare Intel’s first generation i5 processors to their second generation.

Front Side Bus (FSB): The Front Side Bus is the connection point between the CPU and the motherboard chipset. Motherboard specifications will list the FSB, measured in MHz like the CPU clock speed. The combination of FSB speed and a processor’s internal multiplier determines the final speed of the CPU itself. As with processors themselves, FSB speeds have grown astronomically in recent times, with modern motherboards supporting FSB speeds from 533MHz right up to 2000Mhz

Nanometres (nm): The easiest way of measuring the technological intricacy of a CPU is to measure how many specific transistors can fit on the CPU itself. You will see many processors described as 45nm, 32nm or even 22nm. As the technology size in nm drops the size of the transistors declines, this allows a 22nm processor to have many more transistors in the same physical package as a 45nm chip and increase performance massively. The lower the nanometre the processor is generally the more advanced the processor is.

L1/L2/L3 Cache: For the CPU to function it has to be fed with data to process, a bottleneck can easily arise if the data is far away, for example in the systems memory. This will take time to access as the data has to travel through many controllers and a physical distance to the CPU causing a delay. If the CPU doesn’t have to travel outside of itself to get the data it can number crunch more effectively. When the memory is built into the processor it is referred to as cache. As a general rule the more cache a CPU has per core the better its performance in programs.

Almost all processors obtainable to buy today are 64 bit capable. The reason processors and operating systems have moved from 32 bit to 64 bit is largely due to the limits in the amount of memory that a 32-bit CPU can access. A 32-bit CPU can only address 4GB (Gigabytes – 4096MB). For many uses this limit is fine however higher end computers often need 4GB or over to complete complicated tasks or get the best performance out of the very latest games.

A 64-bit processor does not face this problem as it allows the processor to access potentially 16 billion gigabytes of memory (16 Exabytes). Having a 64 bit data path also doubles the amount of data that can be fetched at any one time increasing the performance of a 64-bit processor when running 64-bit applications.

All of the current 64-bit processors are backwards compatible to 32-bit operating systems and programs, although if running a 32 bit operating system they will still suffer from the limit of 4GB of memory. Both CPU and Operating System need to be 64-bit to provide the enhanced compatibility and performance.