Difference between Dual-Core, Core i3, Core i5 and Core i7

By Isaac Meso

The other day I was chatting with a friend of mine and he was really excited about how his new toy that had been shipped from U.K was all powerful. One thing that caught my attention during our chat was when he said that his laptop had a core i7 processor. So I played dumb and asked him what that meant and to my dismay he went completely blank.

My friend is just one of the many people who have little or no idea what these features that are inscribed on our laptops really mean. To shade more light on this topic I would start first by briefly explaining what a core is.

All computers come with processors. The core is that part of the processor that actually performs the reading and executing of instructions. This means that a multi core processor would execute more than one instruction at a time on the same piece of silicon. In addition your computer will read each core as a separate CPU. For instance if your PC is dual-core it means that your machine has two cores in a single processor. The computer reads this as two separate CPUs meaning you can handle multiple tasks at a time.

Now that we have a rough idea what a core is, what is the difference between Core i3, Core i5 and Core i7 and what do they really mean? First of all let us erase this fallacy that is common with most computer users; that the numbers beside the Cores reflect the number of processors in your PC. Core i7 does not have seven processors nor does Core i3 have three processors. On the contrary the number is usually indicative of their processing powers.

The relative processing powers of these cores is usually based on a collection of criteria including, number of cores, clock speed (in GHz), size of the cache, Turbo Boost and Hyper-Threading.
The main difference however between these processor technologies can be pegged on three major factors:

Number of cores

The more cores there are in a processor the more tasks (known as threads) served at the same. For instance Core i3 CPU has the lowest number of cores. It comes with only two cores thus the name dual-core processors. On the other hand Core i5 processors come with 4 cores meaning it comes with 4 processors.

Turbo Boost

The Turbo Boost technology common with Intel products allows a processor to dynamically increase its clock speed whenever need arises. However the maximum amount that a Turbo Boost can raise clock speed at any given time is dependent on the number of active cores, among other factors such as the estimated power consumption.

For instance none of the Core i3 CPUs have Turbo Boost. Core i5 processors on the other hand are equipped with Turbo Boost 2.0 technology. This means that core i5 processors can outrun any Core i3 while Core i7 can outrun any core i5 processors.

Cache size

Last but not leas, cache is that memory inside the CPU that stores data that the processor keeps using over and over again. Cache function like RAM, only that it is faster since it’s located within the processor itself.

With a larger cache more data can be accessed quickly. Core i3 processors have 3MB cache. Core i5s come with 6MB of cache while Core i7s come with 8MB of cache. This is clearly one reason why an i7 will outperform an i5 and an i5 outperform an i3.