It is hard to know how fast any CPU is just by knowing the frequency and number of cores, because the way it moves data across the board is much more important. If you look at two different quad core 4GHz CPUs, one may be 8 times as fast as the other.

To simplify things we list a single performance rating with every CPU. This rating (Passmark CPU benchmark score) is taken from thousands of real users who download a free bench-marking program, then upload their results to the Passmark web site.

The Passmark rating or other similar benchmarks are the only a good way to cut through all the other factors and simply know how fast a processor is. As a reference most modern CPUs range from a passmark score of "3000" for a very basic value priced CPU to over "24,000" for a very high powered CPU.

• (Socket 1151/1150) Core G = 2 Cores / 2 Threads
• (Socket 1151/1150) Core i3 = 2 Cores / 4 Threads
• (Socket 1151/1150) Core i5 = 4 Cores / 4 Threads
• (Socket 1151/1150) Core i7 = 4 Cores / 8 Threads

• (Socket 2011-3) Core i7 = Up to 10 Cores / 20 Threads

 Below we will detail some of the main factors that influence net performance, but you only need to read on if you have an interest in the technology behind the performance.

How a CPU operates
The CPU basically acts like a central information pump inside your system. The pathways on the motherboard are like the tubes that carry this information around to and from the various places on the board (Video Card, Hard Drive, Memory etc.) The information must cycle through this pumping station before it is handled by the devices, so this CPU is critical to system speed.

Older CPUs had a single operating core (like a single pump) that pushed information around the board. The CPUs were not good at predicting what information would be needed in advance and often had to wait for the information to be stacked in the correct place before it could push it through to the correct place on the board. If the size of that particular piece of information was less than could be pushed through in one cycle, the system only pushed through that small piece of information (thread). At that time, the only way that CPUs were made faster was  by increasing the number of times that the CPU pumped information per second. This is the operating frequency of the CPU (Cycles Per Sec. - ie. 2.8GHz)

The first main improvement to CPU technology was to allow two smaller pieces of information (Threads) to be passed through the pump during the same cycle (Hyperthreading / Hyper Transport). This allowed the CPU to pair smaller threads together and push them through at the same time. The next improvement was to increase the amount of pre-staging space for the information. The CPUs had a better potential of having the information ready for the processor to pump when the information was cached in advance. This staging space is called cache memory (i.e. 4MB Cache). As CPUs improve from generation to generation, the ability of how well the CPU is able to predict what information will be needed next is critical to CPU performance, but is very hard to quantify with a specification number.

As CPUs developed it became evident that there was a limit to how fast the CPUs could be cycled. Simply increasing the frequency to infinity was not plausible. The next major improvements came by increasing the number of CPU cores. This was like placing two, three, or four pumps (Dual Core, Triple Core, Quad Core etc.) in the pumping station, each capable of grabbing the information and pushing it through to where it needs to go. More pumps mean more information can be pumped through. As CPUs improve generation to generation the ability of these pumps (cores) to work intelligently together to draw information in the fastest and most efficient way improves. This again is hard to quantify, but it is another reason why more modern generation CPUs are faster than older CPUs with similar specifications.

Most modern CPUs have improved performance further by eliminating the need for some of the information to travel across the motherboard at all. In some cases the memory controller, many chipset functions, and even the graphics processor may reside inside the CPU chip itself.

The assembly process of a CPU is usually represented by a number followed by the letters NM. You will see some of newest CPUs have a number like 14NM where an older CPU might be as high as 130NM. The NM stands for "Nano-Meter" and it is a measurement of approximately how small of a line or pathway can be etched into the silicon wafer that the CPU is printed on. The thinner and more exact the pathway, the less power required, the less heat that is generated, and the greater number of circuits that can be etched into a given space. Generally the lower the NM of the CPU the more modern the design.