There are many factors related with the inside and the outside of the CPU which could affect the CPU performance and also the overall system performance.
The speed of the CPU is measured in megahertz. One megahertz CPU will able to complete one million CPU cycles in one second.
This does not imply that a 2 MHz CPU is twice as fast as a 1 MHZ CPU. The speed of the CPU depends on the work that could be accomplished by a CPU in one clock cycle. A 1 MHz CPU can be faster than a 2 MHz CPU if it is more efficient in a clock cycle. In other terms, if the number of cycles is more, than the performance is better.
Cache memory enables the CPU to access quickly the most recent information. Indeed, it is a major factor which affects the performance of the CPU. The main purpose of the cache is to give access to the recently used information. Though, Cache significantly affects the performance of the CPU, it is used to represent certain difficulties involved in single comparison.
Some caches are bigger when compared to others and a typical L1 cache is of 256kb while a typical L2 cache is of 1MB.In general, the notion is that bigger the size of the cache, better the system performance would be. However, this is not the case always. There is a certain speed of operation for the cache which is similar to that of the core of the CPU. There are some caches which operate at the full speed like that of a CPU while others just operate at a speed which is as half as the speed of the CPU.
It is a bit difficult to compare the size of the cache and there are some PC’s which use an intrinsic cache. The data are duplicated from L1 cache to L2 cache in case of extrinsic cache. This type of CPU will only have the capacity of their L2 caches available.
The Front Side Bus
The connection between the system memory and the CPU is called the Front Side Bus (FBS) and this operates at a speed which is equal to a percentage of the CPU clock speed. The performance of the CPU is made better with a better speed of the front side bus which allows data transfer.
Access speed is associated with the RAM and faster the speed of the RAM, lesser is the time required to access the data. This would make it run at a faster speed.