Best Intel processor: Core i3, i5, i7 and i9 explained

What’s the best Intel CPU?

Need a new CPU? In this guide we’ll look at the best Intel processor options, from chipsets used in cheap laptops to processors you might buy for a PS4-crushing gaming PC.

The aim is to help you find out the kind of processor you’ll need, which one suits how you use your computer. And this should in turn inform the kind of laptop you end up buying, if you’re one of the many who thinks desktop PCs are archaic these days.

Intel’s 10th Gen Ice Lake series is the latest news in the CPU world. You can already find 10th series laptops online, but desktop shoppers can currently choose between 8th generation and 9th generation processors.

First off, let’s tick off a couple of obvious recommendations for some of the most common use cases.

Related: Intel Ice Lake: 10th Generation Intel Core Processor

A snapshot of recommendations

For high-end gaming builds: Intel Core i9-9900KS and 9900Kxp

If only a very high-end CPU will do, consider the Intel Core i9-9900KS. This 8-core, 16-thread monster desktop processor is effectively a ready-overclocked version of the Intel Core i9-9900K. It pairs well with a very high-end graphics card and an effective cooling system.

Many of you may want to consider the cheaper Intel Core i9-9900K too. It has a lower standard clock speed but the real-world power difference isn’t huge in most contexts and it costs less.

Related: Best Laptop Deals

The place to start: Intel Core i5-9600k and i5-9400

The Core i5-9400 is Intel’s baseline mid-range processor. It’s a solid buy. But the current upgrade cost of the Core i5-9600k is so small you may want to consider the jump.

You can pair this processor with a high-end graphics card without risk of regular bottlenecks and the K means the more ambitious among you can overclock the CPU. Out to kit out a mid-range PC? Do look at the price of the vanilla Core i5-9400 too.

Related: Best Laptop 2020

Laptop CPU to look out for: Intel Core i7-10510U

We are already surrounded by new laptops with 10th generation Intel processors. And there are even more models than usual. The Intel Core i7-10510U is one you’ll see in some high-end thin and light laptops like the Dell XPS 13.

Benchmarks show it is around 15-25% faster than the previous i7-8565u.

Best Intel processor: making sense of model names

Intel makes a lot of processors, and unpacking exactly what you are looking at when shopping on Amazon or Ebuyer has never been that easy. There’s a code involved. And Intel just changed how it works. Thanks Intel.

The true basics are still the same, though. There are i3, i5, i7 and i9 CPUs. The higher the number, the more powerful processor. It’s the rest that has changed.

Let’s start with the latest 10th gen chips, crucial information for laptop buyers. You can tell if a processor is part of this generation by the numbers directly after the “i3”, “i5” and so on. If there’s a “10”, we’re dealing with a 10th Gen processor.

The next most important part is the set of numbers and/or letters at the end of the name. If there’s a “G” and a number, this means the CPU has higher-power graphics hardware. And the number after that G tells you how powerful it is, from G1 to G7 up at the top end.

Older eighth-generation laptop CPUs were better defined as being in the “U”, “HQ” or “Y” series. The new G category tells us Intel has focused more on gaming in this generation. It’s not hard to see why. AMD’s Ryzen chipsets have more powerful graphics hardware, and Intel needs to compete.

The aim is to offer on-board graphics with power similar to a discrete card, so you can play AAA games at 1080p without buying extra hardware.

However, there are still U and Y series chipsets in the 10th gen without this gaming focus. For example, the Dell XPS 13 uses the i7-10710U CPU: a name enough ones and zeroes to looks like a binary code mash-up.

Benefits of the latest 10th processors other than raw power include performance-boosting artificial intelligence, Wi-Fi 6 GIG+ for speedier internet connection.

There are different codes for desktop CPUs too. If you see one with an “F” in its name, this means it does not have any graphics hardware attached. This doesn’t matter if you’re planning on building a gaming PC and will use a dedicated card from the off. But you do need some form of GPU.

A “K” tag in a CPU name means the processor can be overclocked, that it is a performance processor for those who will use a good cooling system to make sure the CPU doesn’t overheat if it is pushed beyond its standard limits.

“S” and “X” tags are used to denote extra performance optimisation. And if a CPU has no letters at the end it’s a standard desktop processor. If all this talk of codes sound like overcomplicating something you just want to put into a PC case and work, perhaps one of these standard processors is the right choice.

Related: Best Graphics Cards

Best Intel processor: Core i3 vs i5 vs i7 vs i9 in a desktop

Now that we’ve explained some of the more confusing bits of Intel’s naming conventions, let’s look at which model you should opt for: Core i3, i5, i7 or i9?

As you’d expect, performance increases as you upgrade through the ranks from a Core i3 to a Core i9. But we need to break it down further.

Intel Core i3 desktop processors have four cores. They offer excellent performance for their cost, but they lack a technology found in higher-end CPUs, Hyper-Threading.

Hyper-Threading creates virtual cores to operate in a way that a processor with more cores would operate. Core i3s also have a less powerful turbo boost, used to increase the clock speed under strain for better performance.

Intel Core i5 desktop CPUs have six cores. Like Core i3 models, they don’t offer Hyper-Threading, but they do have a punchier Turbo Boost.

Core i7 processors either six or eight cores, either with or without Hyper-Threading depending on the model you pick.

Intel Core i9 CPUs have eight cores. The i9 is the most powerful option of the Intel Core ranges, so would be the processor to go for if you’re not shy spending money.

So, which do you need? Hyper-Threading would prove most useful for heavy multi-taskers and those who use applications such as video editor Adobe Premiere Pro or 3D rendering software. It’s less useful for games or simple applications, which don’t usually exploit a huge number of cores.

However, this doesn’t mean there’s no benefit to be had from a higher-end CPU if you don’t use such demanding software. Higher-end processors also have higher clock speeds, meaning each of the cores is more powerful, and have a larger CPU cache. This is used to store data handled by the CPU. The larger the cache, the smoother it can operate under pressure.

A normal Core i3 CPU has 6MB, a Core i5 9MB and a Core i7 has 12MB. This a reminder there’s more to a CPU’s performance than just clock speed, and the number of cores it features.
Here’s a run-down of the main models to consider:

Intel Core i3-9100

Don’t turn your nose up at the Core i3 too quickly. It’s a fantastic sub-£100 brain for an everyday PC or low-cost gaming setup. You can use a relatively high-end graphics card, such as an Nvidia RTX 2060 with this CPU, without much bottlenecking. Those looking to build a gaming PC on a budget should also check out the i3-9100F, which leaves out the GPU side.

Intel Core i5-9400
This is the best Intel processor to buy for the majority of people. It’s a powerful 4-core CPU offering great general performance, and it has enough power to pair with some of the most expensive consumer graphics cards around. For around £20 more, you can upgrade to the i5-9500, which has a slightly higher clock speed.

Intel Core i5-9600K
If you want to be able to overclock your CPU significantly, but don’t want to spend thousands on a setup, check out the Intel Core i5-9600K. The price is reasonable, and it’s roughly 15% more powerful than the i5-9400 – even before you start overclocking.

Intel Core i7‑9700k
Let’s get serious. The Intel Core i7-9700K has eight cores, a 4.9GHz turbo mode and 3.6GHz standard clock speed. Intel’s previous generation version of this CPU has six cores, 12 threads, but this time it chose to increase the “real” core count and leave out Hyper-Threading.

Intel Core i9-9900K


Look at the spec sheet, and the i9-9900K seems to be a powerful beast – eight cores and 16 threads are not to be messed with. Benchmark tests testify that this is one of the very best consumer processors for creative tasks. It is not cheap, but promises serious power.

Best Intel processor: Core i3 vs i5 vs i7 vs i9 in a laptop

The situation in laptops is a little different. Right now you’ll find laptops on sale with 8th gen, 9th gen and 10th gen processors. It can be confusing.

You may want to avoid a laptop with an 8th generation chipset, but only if it does not come with a big price reduction. These tend to be slightly older models, you’ll often find excellent deals for them, and these chips are still very capable.

The most powerful new laptops actually use 9th generation chipsets like the Intel Core i7-9750H. You might assume the Intel Core i7-10510U is better because it sounds newer, but the two were actually introduced in mid-2019.

So what’s the difference? The easiest way to understand it is TDP: thermal design power. This tells you how much heat the processor is designed to generate. The Intel Core i7-9750H has a much higher TDP (45W), telling us it’s made for chunkier, more performance-driven laptops.

Low TDP CPUs like the Intel Core i7-10510U are the equivalent of the efficient little engines of a small car. High TDP CPUs are more like sports car engines: more power, more heat, greater energy consumption.

To a large extent the kind of laptop you want will determine the kind of processor you get anyway. Ultra-slim and light ones can’t use high TDP CPUs because they don’t have the cooling systems to deal with the heat. And such processors use significantly more power, so simply aren’t a good fit for a travel laptop that needs to last a full day of work between charges.

Best Intel processor: Real-world performance and gaming

If you do a lot of video editing or 3D rendering, then the greater the CPU power, the better. However, there are more important considerations if you want a productivity PC or a system for games.

An Intel Core i3 has enough power to run Windows 10 well, but you need an SSD rather than a hard drive for slick performance.

The G-series laptop CPUs are also the only models with good gaming abilities baked in. All other Intel CPUs use a version of the UHD graphics chipset, which provide a significantly poorer gaming performance and will unlikely be able to cope with AAA titles.

No Intel desktop CPU is any good for gaming on its own. And if you want to find the right processor to put at the heart of a gaming rig, we’d recommend spending more on the GPU and less on the CPU if the budget is tight.

For example, a Core i3-9100 CPU with an Nvidia GeForce RTX 2070 will provide better frame rates than a Core i9-9900 CPU with a GeForce GTX 1650 GPU. That said, we do recommend treating the Core i5-9400 as a minimum, if you want a CPU to be paired with a very high-end GPU.

With certain games, a lower-end CPU will act as a bottleneck. This is particularly true of games such as Civilization 6 and Total War: Warhammer 2, as a result of all the background calculations involved. Most glossy action adventure games are a lot more GPU-led, and will run fine with a Core i3.

Best Intel processor: Want to get a little deeper?

Primer: what is clock speed? The GHz figure represents the number of clock cycles (calculations) a processor can manage in a second. Put simply, a bigger number means a faster processor.

For example, 3.6GHz means 3,600,000,000 clock cycles. This figure shouldn’t be used to compare processors from different families, generations or manufacturers, however. Bigger isn’t better when comparing AMD and Intel, or 2nd-gen to 9th-gen Intel processors. Different processor families have different levels of efficiency, so how much they get done with each clock cycle is more important than the GHz number itself.

Turbo Boost dynamically increases the clock speed of Core i5 and i7 processors when more power is required. This means the chip can draw less power, produce less heat (most of the time) and only boost when it needs to.

Turbo Boost means you can’t just look at standard clock speed. For example, although a Core i3-8100 runs at 3.6GHz compared with 1.6GHz for the Core i5-7600, the i5 chip can boost up to 3.6GHz when required, so will end up being quicker since it also has more cores.

The more a processor boosts its clock speed, the more heat it will produce. As such, the processors can only Turbo Boost for a limited time, while they remain within a certain temperature range. During long periods of heavy processor activity using all a processor’s cores – such as video encoding – a chip may not Turbo Boost much at all, since it might be too hot to do so safely.

Turbo Boost is a significant part of the reason Core i5 and Core i7 processors outperform Core i3 models in single-core-optimised tasks, even though they have lower base clock speeds.

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