Which Intel Core CPU is the best? How do I decide between a Core i3, i5, i7 or i9?

From the moment you decide that your current Intel processor just isn’t up to par and start investigating an upgrade to your current laptop or desktop, you’re often bombarded with technical jargon.

Quad-cores. Hyper-Threading. Turbo-Boosting. Cache size.

Even for the technically literate, there’s a very real risk that you’ll become bogged down by the details here. Unfortunately, when it comes to picking the right Intel CPU, those details matter a lot. Often-times, getting by without a basic understanding of them isn’t really a viable option.

So, what is the difference between an Intel Core i3, i5, i7 and i9? What do vendors mean when they talk about generations of chipsets? What is hyper-threading and how do you tell if your clock speed is any good?

This article is a follow-up to our older Haswell-based and Kaby Lake Intel CPU comparisons that can be found here and here.

Understanding your current Intel processor

Before looking at buying new processors, it’s worth giving your current Intel CPU a quick once-over to get a better picture of where your PC’s power and performance level currently sits. The fastest way to do this is usually to open up your Control Panel, go to “System and Security” subheader and select ”System”.

From here, you’ll get a quick overview of the CPU, RAM and OS currently installed on your PC. Under processor, you should be given the full title for your current Intel CPU. For example, Intel Core i7-4790 or Intel Core i7-8500U. You’ll also be given a rough indicator of your CPU’s clock speed, measured in Ghz. We’ll come back around to this and go into a bit more detail later in this article.

The long string of numbers attached to your CPU’s name might initially seem a bit intimidating and/or confusing. However, understanding what those numbers mean isn’t actually all that difficult. Breaking things down using our earlier example:

The first part of the name - in this case, “Intel Core” - refers to the fact that this CPU is made by Intel and is part of their Core series of processors. The Core is Intel’s biggest and most-popular range of products, so you’ll probably find this prefix on most for desktops and notebook PCs.

Note - Intel do offer other ranges of processors like Celeron, Pentium and Xeon. However, this article is focused on understanding Intel’s Core processors.

Then, “i7” refers to the style or design of the microarchitecture inside the CPU. If it helps, think of this as similar to how different cars feature different classes or kinds of engines. Within the big-picture context, these engines serves the same function. However, the exact way in which they go about it will vary between car brands. In Intel’s case, the different classes (either i3, i5, i7 or i9) of Core brand CPUs are varied by their specs: the number of cores, clock speed, cache size, as well as support their for more-advanced technical features like Turbo Boost 2.0 and Hyper-Threading. As a general rule of thumb, Core i5 and i7 desktop processors are usually quad-core while lower-end Core i3 desktop processors are dual core.

Next, you’ve got the SKU and gen-markers. Just to recap, in our earlier example, this would be “4790”. The first digit here - “4” - refers to the generation of the CPU while the rest - “790” - is the SKU, which is sort of like a serial or ID number. This means that, in our example, our Intel Core i7 is a fourth-gen one.

Last but not least, there’s the suffix. In our example, there isn’t one. However, other processors - like the “Intel Core i7-8650U” - do include a number at the end. In this case, the "U" stands for “Ultra Low Power”.

However, the various suffixes that Intel uses - and their meanings - can often shift between generations. So if you’re looking to decipher the one on your current CPU, we’d recommend consulting Intel’s own list of suffixes here.

So there you go. You now understand what you’re looking at when you read the name of your current Intel processor. Now, what do you look for in an upgrade?

How much does the generation of my CPU matter?

Quite a lot. The short version when it comes to “gens” is that higher is usually better. However, the exact extent of those improvements will vary quite a bit.

For example, according to Intel, the eight-gen Intel Core processors offer significant speed improvements compared to their seventh gen counterparts of up to 40%. Obviously, this number is going to vary a lot based on which two processors you compare, since the exact SKUs Intel use can vary considerably between generations. Just because there is an Intel Core i7-8850U doesn’t mean there’s a corresponding Intel Core i7-7850U.

Regardless, as a rule of thumb, having a higher-gen CPU means the processor is more recent - which means you’ll benefit from more recent technical and design advancements - which means you’ll probably end up getting better performance from your PC.

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Tags intelIntel CoreIntel Core ProcessorsIntel Core i3Intel Core i9i5 and i7

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Fergus Halliday
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