Difference between Intel Cores: Core i3, Core i5, Core i7

Core i7s are better than Core i5s, which are in turn better than Core i3s. Nope, Core i7 does not have seven cores nor does Core i3 have three cores. The numbers are simply indicative of their relative processing powers.

Their relative levels of processing power are also signified by their Intel Processor Star Ratings, which are based on a collection of criteria involving their number of cores, clockspeed (in GHz), size of cache, as well as some new Intel technologies like Turbo Boost and Hyper-Threading.

Core i3s are rated with three stars, i5s have four stars, and i7s have five. If you’re wondering why the ratings start with three, well they actually don’t. The entry-level Intel CPUs — Celeron and Pentium — get one and two stars respectively.

Note: Core processors can be grouped in terms of their target devices, i.e., those for laptops and those for desktops. Each has its own specific characteristics/specs. To avoid confusion, we’ll focus on the desktop variants. Note also that we’ll be focusing on the 2nd Generation (Sandy Bridge) Core CPUs.

The more cores there are, the more tasks (known as threads) can be served at the same time. The lowest number of cores can be found in Core i3 CPUs, i.e., which have only two cores. Currently, all Core i3s are dual-core processors.

Currently all Core i5 processors, except for the i5-661, are quad cores in Australia. The Core i5-661 is only a dual-core processor with a clockspeed of 3.33 GHz. Remember that all Core i3s are also dual cores. Furthermore, the i3-560 is also 3.33GHz, yet a lot cheaper. Sounds like it might be a better buy than the i5.

At this point, I’d like to grab the opportunity to illustrate how a number of factors affect the overall processing power of a CPU and determine whether it should be considered an i3, an i5, or an i7.

Even if the i5-661 normally runs at the same clockspeed as Core i3-560, and even if they all have the same number of cores, the i5-661 benefits from a technology known as Turbo Boost.

What the difference between Intel Cores: Intel Turbo Boost

The Intel Turbo Boost Technology allows a processor to dynamically increase its clockspeed whenever the need arises. The maximum amount that Turbo Boost can raise clockspeed at any given time is dependent on the number of active cores, the estimated current consumption, the estimated power consumption, and the processor temperature.

For the Core i5-661, its maximum allowable processor frequency is 3.6 GHz. Because none of the Core i3 CPUs have Turbo Boost, the i5-661 can outrun them when it needs to. Because all Core i5 processors are equipped with the latest version of this technology — Turbo Boost 2.0 — all of them can outrun any Core i3.

Single/Dual/Quad Core

The other important point to consider is the number of cores(CPUs) a processor has. For the layman, a CPU is the brain behind the computer. The faster is the CPU, faster is the response time of the computer. Technological limitations however do not allow the CPU to go over a speed of 4GHz at which huge amount of heat is generated. Therefore processor manufacturers like Intel and AMD packed more CPUs into the machine(dual core = 2 CPU and quad core = 4 CPU) to increase the performance.

In order to linearly increase the system performance with the number of cores, it is also important to use software applications that can use the multi-core functionality like Adobe Photoshop and many computer games. For traditional applications there will be no noticeable difference in speed even when using a multi core system. So for people who use more of Photoshop, a multi core processor is a must. Operating Systems like Windows 7 have also been modified to fully take advantage of multi core and many applications are being modified to work efficiently with multi-core systems. So it is advisable and better to buy a dual core processor for most users but for users fond of computer games etc. a quad core processor is beneficial.

Cache Memory/RAM

One can think of the cache as a substitute for short term memory. Whatever is stored in the short term memory can be easily and speedily recalled without having to make an effort of thinking and retrieving it from the long term memory. The larger the short term memory, better the response time of the system. So higher is the processor cache, better is the processor performance. TDP, multi-core and cache are general terms which can be used to compare all types of processors. But there are some Intel specific terms which are necessary to compare Intel processors like Turbo Boost and Hyper-threading.

Tips:

Core i3 The core i3 processors are suitable and sufficient for almost all everyday tasks and are also among the cheapest of these Intel core processors. The article here provides a list of the best mini laptops based on core i3 processors.

Core i5 The ultra low voltage processors although have a lower clock speed leading to excellent battery life of about 6-10 hrs, the Turbo Boost technology compensates for the lower clock speed when the laptop is plugged-in. These processors therefore combine the benefits of longer battery life when on the move and good performance when the laptop is on charge.

Core i7 The processors in the Extreme series pack the power of desktop processors making it possible to perform every task traditionally reserved only for desktops. But laptops with these processors are extremely costly and will be difficult to find anything below Rs. 60000.