The Differences between Intel’s Core CPUs

Greetings everybody! I’m still alive! I only made a new record for blog inactivity because graduation exams kicked in, while I also had to prepare for life in the US and my university application there. All’s pretty much done now thankfully, so I can go back to blogging again. Anyway, when I was advising a build for one of my clients, he suggested me to write a blog on the differences between Intel Core i5 and i7 chips for easier references, so here it is!

But first, before we get to the core of what’s different between the Core chips, let’s go through Intel Core series’ naming convention first, so we know exactly what kinds of chips there are.

(NOTE: This naming section does NOT concern Intel Core M chips, which have the format “Intel Core M-xYxx” or “Intel Core mx-xYxx”, which are extremely low-power laptop/mobile CPUs)

Intel Core CPU Naming

The full name of a Core series CPU should be something like this:

Intel Core Naming.png

Yes, I know my graphic is a bit messy, sorry for that. Anyway, I’ll go into details on each part of the CPU name a bit more:

  • The Sub-Brand part, also officially called the Brand Modifier, is the i3/i5/i7 part we always know. It’s a tiering scheme from Intel to make things easier for the user, much like how AMD named their 200-300 series cards R5/R7/R9 xxx.
  • The Generation part is self-explanatory. However, you must take note that Refresh and Extreme Edition CPUs (more on that later) will have their generation number one unit higher than their actual generation. For example, a Broadwell (5th generation) Extreme Edition CPU will have the name Intel Core i7-69xxX
  • The last three numeral digits in the name are known as the SKU Number. It’s basically the CPU’s code, and generally, the higher the SKU number, the higher performance the CPU will have in the same generation.
  • This is not official, but I also call the first digit of the SKU Number the Tier of the CPU. Normally, tiers 1-3 are for i3 chips, tiers 4-6 are for i5 chips, tier 7 is for i7 chips, tier 8 is for i7 Refresh chips and tier 9 is for i7 Extreme Edition chips (more on those later). NOTE: This “Tier” part is only meaningful for desktop CPUs!
  • The capital letter at the end of the name, which may or may not be present, denotes the CPU type. I’ll have a whole section on this later.

Alright, now that we are done with the naming, let’s get to the meat of this post: the basic differences of i3, i5 and i7 CPUs.

Intel Core i3


  • Currently, all i3 CPUs only have 2 cores, which means it can physically only process 2 streams of data at once.
  • However, i3 CPUs do support hyper-threading, which tricks the system into thinking each physical CPU core is actually two “logical” cores, thus allowing the computer to send 4 streams of data for the CPU to process, a.k.a. 4 “threads”, putting more stress on the CPU cores and forcing them to work more with less latency (on every thread, a packet of data has to be processed completely before the next packet can start being processed, so if a CPU core can process 2 packets of data at once, it’ll be more efficient), which in turn increases performance on programs that use multiple cores. Thus, i3 CPUs are noted as “2 cores, 4 threads” in system information programs.
  • This is a minor concern, but i3 CPUs can have 1.5MB or 2MB of cache (or L1 Cache) per core. Cache is a small piece of memory built into the CPU that stores copies of data in the RAM, and this data can be received by the CPU at a much faster speed.


Intel Core i5


  • All modern i5 desktop CPUs have 4 cores, while i5 laptop CPUs can have 2 or 4 cores.
  • However, i5 CPUs do NOT support hyper-threading, so they will be recognized as, for example, “4 cores, 4 threads” in system information programs.
  • Instead, i5 CPUs support Turbo Boost. Turbo Boost dynamically adjusts a CPU core’s clock speed, increasing performance but also power consumption and heat, when performance is needed. For example, an i5-6600 has the base clock speed of 3.3 GHz, but a boosted clock speed of 3.9 GHz. This means that its cores will always work at 3.3 GHz, but will boost to 3.9 GHz on heavy tasks, such as video rendering or heavy gaming. To stabilize power consumption and heat, the CPU can also boost the clock speed of the primary core but leave the other cores at base clock, while running heavy single-core programs, such as most AAA video games. Also, please note that clock speed comparison is only relevant in the same family of CPUs, and is not an absolute reference to a CPU’s performance.
  • Like i3 CPUs, i5 CPUs can also have 1.5MB or 2MB of cache per core.


Intel Core i7


(Note: This section is only for “regular” i7 CPUs. For Refresh and Extreme CPUs, see the section below)

  • All modern i7 desktop CPUs have 4 cores, while i7 laptop CPUs can have 2 or 4 cores.
  • i7 CPUs support both Hyper-Threading and Turbo Boost. This is the main reason why people may say an i7 is no different to an i5 for games but better for other CPU-intensive programs, since most games are still single-core programs and thus don’t benefit much from Hyper-Threading. However, upcoming games are starting to support asynchronous compute and multiple cores, so i7 CPUs can also be better for games than i5 CPUs in the near future.
  • All i7 CPUs have 2MB of cache per core.


Intel Core i7 Refresh and Intel Core i7 Extreme


Finally, the top-end of CPUs! To be honest though, these CPUs are so different to regular i7 CPUs that they should’ve been called i9. In fact, they are even more different to i7 CPUs than i7 CPUs are different to i5 or even i3 CPUs!

  • On desktops, these tier 8-9 CPUs require the discrete X series chipsets, so they will also need different motherboards and in some cases even different RAM generations, and won’t be compatible with systems for other Intel Core CPUs.
  • These CPUs can have any number of cores, currently ranging from 4 to 10, but may have even more cores in the future.
  • Of course, these CPUs support both Hyper-Threading and Turbo Boost.
  • These CPUs have 2.5MB of cache per core.
  • The Extreme Edition CPUs are also notorious for their high price, with the latest ones usually costing around $1000 or more, as much as thrice the price of regular i7 CPUs!


Common CPU Types

And finally, to conclude this blog post, here’s a list of common CPU type indicators and what they mean, in order of performance:

Desktop CPUs:

  • S and T chips are low-power desktop chips with slightly reduced performance. However, S chips are slightly more performance-optimized than T chips.
  • Blank chips are regular, locked desktop chips (do not support overclocking). All CPU types in this section are locked unless otherwise stated.
  • K and C (5th generation (Broadwell) only) chips are unlocked desktop chips (support overclocking).
  • X chips are Extreme Edition desktop chips. These are the strongest CPUs available in this series, and of course, are also unlocked.

Laptop/Mobile CPUs:

  • U and M (4th generation (Haswell) only) chips are regular mobile chips, with U CPUs having lower performance and power consumption in the fourth generation.
  • MQ chips are quad-core, high-performance mobile CPUs.
  • HQ chips are quad-core mobile CPUs with HD 5xx, Iris or Iris Pro graphics.
  • HK chips are like HQ chips but unlocked.
  • MX chips are Extreme Edition, unlocked mobile CPUs.
The Asus ROG GX700, a laptop with the rare i7-6820HK, as well as a discrete watercooling unit!


And that’s it for today’s blog post! To make up for the long hiatus, I’ll have more posts in the near future, so please stay tuned, and thank you again for reading and supporting me so far! ^^


4 thoughts on “The Differences between Intel’s Core CPUs

    1. This article was written like a year ago, and I haven’t updated it… A lot of things have changed since then and, to be honest, very few things in this article will still hold true for the latest Kaby Lake and Coffee Lake processors… ^^” Once everything is released, I may consider writing a different article altogether on this topic.


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