If you are choosing between two different types of Mac, or two generations of the same Mac, you may be wondering just how much of a difference the processors will make. In this article we will endeavour to clarify the differences between the generations of Intel processors, what you can expect from an i3, i5, i7, i9 or a Xeon processor, why it matters how many cores you get, what Turbo Boost really means, and whether you should wait for Apple Silicon.

There are so many different terms used to describe the processor in the current crop of Macs that trying to figure out which is best for you is enough to make your head spin. So which processor should you choose? And does it really matter? Plus, with Apple announcing that it will not be using Intel processors inside future Macs, instead preferring to use its own Apple Silicon processors, that means the question of which processor to choose is more complicated than ever. Luckily we are here to help.

What generation of processor is in my Mac?

Apple has been using Intel processors inside Macs since January 2006. As each new generation of processor arrives inside a Mac users benefit from improvements such as improved speed, support for more cores, support for more RAM, improved power consumption and energy management, and so on. The latter being good for battery life. 

In recent years Apple has specified a processor generation for each Mac in its marketing materials. So when you are buying a new Mac you will probably see a description such as 2.0GHz quad-core 10th-generation Intel Core i5 processor.

Unfortunately this information is not so easy to check on a Mac itself. Normally we would turn to the About This Mac information (click on the Apple logo in the left corner of the screen > About This Mac) for details of the specs of a machine, but there is no processor geneation listed here. This means that it can be pretty trickly to find out which generation of processor you have inside a Mac. If you want to find this out we suggest you read our guide to how to check the specs of your Mac as we cover how to find out which processor you have there.

Another way to tell which generation of processor you have is to find out how old the Mac is. Here's how that Intel processor line up has looked since around 2011:

  • 1st Generation – Nehalem
  • 2nd Generation – Sandy Bridge
  • 3rd Generation – Ivy Bridge
  • 4th Generation – Haswell
  • 5th Generation – Broadwell
  • 6th Generation – Skylake
  • 7th Generation – Kaby Lake
  • 8th Generation – Coffee Lake
  • 9th Generation – Coffee Lake Refresh
  • 10th Generation - Ice Lake

The names Sandy Bridge, Ivy Bridge, Haswell, Broadwell, and Skylake are Intel's codenames for its processor architectures. Nehalem and Sandy Bridge date back to 2011, and Ivy Bridge was an update to Sandy Bridge in 2012.

Haswell came in 2013 and was a major re-design of the Ivy Bridge architecture. Broadwell, in 2015, was a relatively minor update to Haswell. Skylake first appeared in late 2015, then in 2017 Kaby Lake processors started to appear.

Kaby Lake was followed by Coffee Lake. Coffee Lake brought some big changes, with 6-core options and more quad core options at the entry-level. The initial Coffee Lake release was the 8th generation of Intel processors. In autumn 2018 the 9th generation launched - known as the Coffee Lake refresh - which added 8-core i9 processor options.

Moving on to the next generation of Intel processors after the Coffee Lake refresh is not so simple. Next in succession was supposed to be Cannon Lake, but Intel as encountered a number of problems with Cannon Lake and in the end the line was discontinued before it even arrived in a Mac.

Ice Lake followed Cannon Lake at the end of 2019. The 10th generation Intel processors found inside 2020 MacBook Air and the 2.0GHz MacBook Pro models are Ice Lake.

The next generation of Intel processors will be Tiger Lake - but it is likely that by then Apple will have switched to Apple Silicon processors inside its Macs. We'll discuss Apple Silicon in more detail below, but we also have this article: Complete Guide To Apple Silicon And Apple's ARM Mac plans.

There is another set of Intel processors used inside some Macs. The Mac Pro and iMac Pro use Intel Xeon processors, which are better suited to workstations and servers.

The 2019 Mac Pro offers 8- to 28-core Intel Xeon W processors, while the iMac Pro, offers Intel Xeon W processors that range from 8- to 18-cores.

Xeon workstation processors have different codenames to the processors listed above but are based on the same Intel architecture.

MacBook

What is Apple Silicon?

Apple Silicon is the name Apple has given to the processors it will be be designing for use inside its Macs. Apple is basing these chips on the ARM architecture so you may see them referred to as ARM processors, SoC (system on chip) or SiP (system in package).

We don't yet know a lot about what the first Apple Silicon processor will offer, other than what Apple revealed about it at WWDC. The company said it will "transition the Mac to its world-class custom silicon to deliver industry-leading performance and powerful new technologies."

Apple claims that its family of SoCs for the Mac will give the Mac "industry-leading performance per watt and higher performance GPUs — enabling app developers to write even more powerful pro apps and high-end games".

The transition will also enable access to technologies such as the Neural Engine. This means that developers will be able to benefit from machine learning when designing their apps. The move also means there will be a common architecture across all Apple products - so developers can write and optimise software for the entire Apple ecosystem.

Apple isn't new to chip design: The company already makes its own ARM-based processors for the iPhone, iPad, Apple Watch, HomePod, Apple TV.

The first processor designed by Apple was the A4, which appeared inside the iPhone 4 back in 2010 (and subsequently the iPad, iPod touch and Apple TV). The latest A-series chip is the A13 Bionic that features in the iPhone 11 series.

Apple also makes S-series chips for use inside the Apple Watch, and W-series and H-series for use inside the AirPods. There is also a U-series chip used for Ultra Wideband technology in the iPhone 11-series.

In fact, there are already Apple ARM-based processors inside Macs. The T1 and T2 are ARM-based security related chips that appear in various Macs. The T1 chip first appeared inside the MacBook Pro in 2016. It had the sole purpose of running the System Management Controller (SMC) and the Touch ID sensor. Its successor, the T2 adds an image signal processor, audio controller, a SSD controller, secure boot and encryption features, and "Hey Siri" support.

We take a look at the rumours about the first Mac to use Apple Silicon here.

How will Apple Silicon compare to Intel?

The Intel processors that Apple has used in its Macs since 2006 are x86 chips. The processors Apple makes in house are ARM-based. While x86 chips are better suited to more complex applications, for the majority of Mac-users ARM chips should be suitable for their needs. ARM has the benefit of being more power efficient and because they wouldn't require a fan for cooling switching to ARM processors could allow for smaller and thinner Macs.

You might think that this means ARM processors aren't powerful enough to power a Mac, but the A12Z chip found in the iPad Pro - and now featured inside the special developer Mac mini - is almost as powerful as the processor inside the MacBook Pro from a couple of years ago.

MacBook Air or MacBook Pro

How to choose which Mac processor

You now hopefully understand the differences in processor generation, but that's not everything you need to know before you can decide which Mac processor will best suit your needs.

We will look at a number of other differences between processors, including the processor speed (in GHz) and the speed that can be claimed if Turbo Boost is active.

We will also look at the different processor types in each generation. For example, you can choose from an i5 and an i7 chip and even an i3 or i9 chip.

The other big difference will be the number of cores available, with dual-core, quad-core, and even 8- 12- and 18-cores available. We'll also examine this below.

For context, here's a list of the various processors you will find in the current line up of Macs and the build-to-order options (at least when we updated this article in July 2020). As you will see there is a lot of variety in terms of processor speed, number of cores, Turbo Boost figures and whether it is an i3 or an i9.

MacBook Air (buy from Apple here)

  • 10th-gen, 1.1GHz Dual-Core, i3, Turbo Boost: 3.2GHz
  • 10th-gen, 1.1GHz Quad-Core, i5, Turbo Boost: 3.5GHz
  • BTO: 10th-gen, 1.2GHz Quad-Core, i7, Turbo Boost: 3.8GHz

13in MacBook Pro (buy from Apple here)

  • 8th-gen, 1.4GHz Quad-Core, i5, Turbo Boost: 3.9GHz 
  • 10th-gen, 2.0GHz Quad-Core, i5, Turbo Boost: 3.8GHz 
  • BTO: 10th-gen, 2.3GHz Quad-Core, i7, Turbo Boost: 4.1GHz 

16in MacBook Pro (buy from Apple here)

  • 9th-gen, 2.6GHz 6-Core, i7, Turbo Boost: 4.5GHz 
  • 9th-gen, 2.3GHz 8-Core, i9, Turbo Boost: 4.8GHz
  • BTO: 9th-gen, 2.4GHz 8-Core, i9, Turbo Boost: 5.0GHz

Mac mini (buy from Apple here)

  • 8th-gen, 3.6GHz Quad-Core, i3, No Turbo Boost
  • 8th-gen, 3.0GHz 6-Core, i5, Turbo Boost: 4.1GHz 
  • BTO: 8th-gen, 3.2GHz 6-Core, i7, Turbo Boost: 4.6GHz

21.5in iMac (buy from Apple here)

  • 7th-gen, 2.3GHz Dual-Core, i5, Turbo Boost: 3.6GHz 
  • 8th-gen, 3.6GHz Quad-Core, i3, No Turbo Boost
  • 8th-gen, 3.0GHz 6-Core, i5, Turbo Boost: 4.1GHz 
  • BTO: 8th-gen, 3.2GHz 6-Core, i7, Turbo Boost: 4.6GHz

27in iMac (buy from Apple here)

  • 8th-gen, 3.0GHz 6-Core, i5, Turbo Boost: 4.1GHz 
  • 8th-gen, 3.1GHz 6-Core, i5, Turbo Boost: 4.3GHz 
  • 9th-gen, 3.7GHz 6-Core, i5, Turbo Boost: 4.6GHz 
  • BTO: 9th-gen, 3.6GHz 8-Core, i9, Turbo Boost: 5.0GHz

iMac Pro (buy from Apple here)

  • Xeon W, 3.2GHz, 8-core, Turbo Boost: 4.2GHz 
  • BTO: Xeon W, 3.0GHz, 10-core, Turbo Boost: 4.5GHz 
  • BTO: Xeon W, 2.5GHz, 14-core, Turbo Boost: 4.3GHz
  • BTO: Xeon W, 2.3GHz, 18-core, Turbo Boost: 4.3GHz

Mac Pro (buy from Apple here)

  • Xeon W, 3.5GHz, 8-core, Turbo Boost: 4.0GHz 
  • BTO: Xeon W, 3.3GHz, 12-core, Turbo Boost: 4.4GHz 
  • BTO: Xeon W, 3.2GHz, 16-core, Turbo Boost: 4.4GHz
  • BTO: Xeon W, 2.7GHz, 24-core, Turbo Boost: 4.4GHz
  • BTO: Xeon W, 2.5GHz, 28-core, Turbo Boost: 4.4GHz

In order to decide which processor best suits you we suggest you run though the following options: GHz, Turbo Boost, i5 vs i7, Cores and Cache - each of which we will look at in detail below.

iMac processor

How many GHz?

GHz reflects the number of clock cycles per second. So a 2.3GHz processor's internal clock beats 2.3 billion times per second. Hence people referring to the number of GHz as the clock speed.

Each range of Macs usually has more than one option in terms of GHz.

Sometimes it will look like a more powerful Mac has a slower clock speed. This is invariably due to the Mac in question having more cores available. For example, the 3.1GHz 6-Core iMac costs considerably more than the  3.6GHz Quad-Core model. At first glance that might look like a bad deal, but that's six 3.1GHz cores, rather than four 3.6GHz cores. And the more cores the better, as we will explain below.

iMac or MacBook Pro

What is Turbo Boost?

Another thing to note in terms of GHz is the Turbo Boost figure. The simplest way to think of Turbo Boost is as a way of safely over-clocking the cores on a processor. This figure can sometimes give a clue as to how one generation's processor compares to the next.

The Turbo Boost controller samples the power consumption and temperature of the cores hundreds of times a second while monitoring the demands made of them by software. If any of the cores are being driven to their theoretical maximum, Turbo Boost can, if enough power is available and the temperature is at a safe level 'over-clock' the core and enable it to work faster.

So the eight cores in a MacBook Pro's 2.3GHz 8-Core i9 processor can, if needed, be pushed to 4.8GHz subject to power consumption and heat dissipation.

One thing to note, some processors won't be able to Turbo Boost. These i3 processors, found in the 3.6GHz Quad-Core iMac and the 3.6GHz Quad-Core Mac mini do not include Turbo Boost, so the 3.6GHz speed is never going to be over-clocked. However, that may not matter to you if you won't benefit from Turbo Boost.

Why would you need Turbo Boost? Turbo Boost kicks in when you aren't using all the cores, so the clock speed can be incresed on the cores that are in use. So, Turbo Boost is a feature that will benefit you most if you aren't using applications that use multiple cores.

Why you might not want Turbo Boost? When Turbo Boost is in use your computer will be using more power, so if you have a laptop it might not be in your interest to have Turbo Boost.

iMac 2019

Core M, i3,  i5, i7, or i9?

Wondering how i5 is better than i7, or if i3 is going to be inadequate? We look through the different processors right up to i9.

Core M

Intel makes mobile versions of its chips. The M, which appeared in the first Retina MacBook when it launched in 2014, was the first Intel laptop chip that didn't need a fan to cool it. Its power efficiency is what allowed Apple to build a notebook that was thin, weighed only 900g, and clocked up 9 hours of battery life while running at a reasonable speed.

There were three M processors with increasing performance: m3, m5 and m7. The M processors aren't currently being used by Apple.

Core i3

There are a couple of Macs that currently ship with i3 processors, which, as we said above, don't feature Turbo Boost.

Core i5

The majority of Macs use Intel's i5 processors. Right now the i5 tends to be quad-core or 6-core, but you'll notice that there is an old i5 processor in the entry-level iMac, with a dual-core (it's an older generation).

Core i7

i7 used to be the big differentiator, but there aren't currently any i7 processors in the Mac range. However, it's worth looking out for if you are thinking of purchasing an older Mac. This is because, in older generations of Macs, when it came to quad-core the i5 and i7 versions were not equal.

The Quad-Core i7, which was once used in the 15in MacBook Pro offered some features that the Quad-Core i5 didn't, one of which was Hyper threading, which we discuss below.

Another difference was the size of the cache, which we will also discuss later.

Thanks to these features, i7 processors were better for multitasking, multimedia, high-end gaming, and scientific work.

Core i9

Intel's i9 processors are the new kids on the block. They arrived with the 9th generation Coffee Lake refresh, and have up to 8-cores.

Core i9 is faster, but you don't necessarily need it and that extra power will mean a sacrifice when it comes to battery life.

Xeon

Xeon processors are workstation or server processors. Xeon processors support more memory than the i5/i7/i9 processors - the 2019 Mac Pro will offer up to 1.5TB RAM. You will also find more cores available on Xeon processors, up to 28-cores in the Mac Pro.

How many cores?

Among the Macs on sale currently you will generally find dual-core, quad-core, 6-core, and 8-core options.

If you need more cores, the Mac Pro offers a Xeon processor with 8, 12, 16, 24, or 28-cores.

The more cores in your CPU the faster it will perform (and the more energy it will guzzle).

iMac cores

CPU Cache

The more processor cache you have the better. Cache is on-board memory and it helps the processor deal with repetitive tasks faster, because information can be held in the memory. Greater amounts of cache will also help with multitasking, because several tasks can be run simultaneously.

Hyper threading

Hyper threading allows the processor to handle twice as many 'streams' as it has cores, by fooling software into thinking it has twice as many cores. So a quad-core processor with hyper threading should be able to execute four times as many sets of instructions in a given time period as a dual-core processor with the same clock speed but without hyper threading.

This means that a quad-core i7, for example, can act like it has eight cores, but a quad-core i5 will only be able to use the four cores available to it.

Which Mac Processor?

The Mac processor that best suits you will be determined by your needs. We would generally advise that you buy the best option you can afford though - based on the idea that doing so will futureproof you for longer. We'd also normally check whether an update is anticipated for the Mac you are considering buying - because there is nothing worse than buying a new Mac only for Apple to update the processors the next month.

Right now there is a big question though - since Apple has announced its plans to move to its own Apple Silicon processors inside Macs should you wait for the first non-Intel Macs to launch? We discuss this question here: Should I buy an Intel Mac. We suggest that your decision here should be based on how many years you think you will be using the Mac for, and whether you are prepared to be one of the guinea pigs using one of the first ever Apple Silicon Macs.