The cores in your computer's CPU have evolved steadily over the years. We first had single-core CPUs, but that quickly evolved to multithreading and, from there, multi-core setups, starting with dual-core designs before launching into quad-core, octa-core, and further.Intel's 12th-Gen CPUs, and then 13th-Gen, treated us to an unexpected yet pleasing twist: two different kinds of cores in one CPU package: E-Cores and P-Cores.But what's an Intel E-core and a P-core anyway? And more importantly, why should you care?

Why Do Intel CPUs Come With Different Cores Now?

Dell motherboard and CPU

Up until this point, x86 computers used core layouts comprised of cores that are, for the most part, identical to one another. Each core has the same processing capacity and clock speed, silicon lottery notwithstanding. Since multi-core designs aim to spread tasks between all cores to crunch through things faster, it's a design that makes sense.

That was until British semiconductor developer Arm decided to switch things up with what's known as a big.LITTLE architecture. ARM architectures effectively have two sets of cores doing different tasks. The bigger, performance-focused cores handle the heavier tasks, while the smaller, efficiency-oriented cores take up background tasks while consuming way less energy. The combination allowed Arm to boost its chip performance while keeping power consumption low.

This is exactly what Intel is doing here. You have two sets of cores doing different things. Intel initially experimented with this layout with its mobile Lakefield chips, the Intel Core i5-L16G7 and the Core i3-L13G4. Those chips came with one P-core and four E-cores. While that initial incarnation was a mixed bag in performance, the company did it again with its main lineup of chips, Alder Lake, and then with its successor, Raptor Lake, where it was widely praised.

AMD is rumored to be doing this design for its Ryzen chips sooner than later, but the company hasn't announced its plans to do so just yet. However, Hardware Times reported on an AMD CPU allegedly using a big.LITTLE design, first spotted by InstLax64 on Twitter.

Intel's E-core and P-core chip configuration works almost identically to what Arm has been doing for years with big.LITTLE, and so far, it has shaped up to be a worthy upgrade from other x86 core layouts.

What Is an Intel P Core?

Bottom of LGA Intel CPU

Let's start by laying down what a P-Core, or performance core, is.

On Intel's set of two different core layouts, P-cores are the strongest cores on the chip. These are the ones that will guzzle the most energy, run at the highest clock speeds, and overall crush through instructions and tasks. These are the "main" cores in the chip doing most of the hard work, lifting the heavier weight. On Intel's newest CPUs, P-cores are based on Intel's Golden Cove or Raptor Cove microarchitecture (depending on whether it's 12th-Gen or 13th-Gen, respectively), succeeding the older Cypress Cove cores used in Rocket Lake (11th-Gen) chips.

P-cores will typically take care of heavier tasks, such as games or heftier processing loads, as well as other workloads that generally benefit from single-core performance. In the past, when cores on Intel chips were all identical, all of a PC's instructions were distributed between all cores equally. Additionally, P-cores also offer hyperthreading, meaning each core will have two processing threads for tackling loads better.

What Is an Intel E Core?

Intel Core i5 CPU

P-Cores are, really, the same cores we've known for years. The real star of the show here is the Intel E-cores, or efficiency cores, which are the true new big thing in this CPU design. While P-cores get all the headlines and all the attention, E-cores take a step back to tackle other kinds of everyday tasks.

E-cores are smaller and weaker than P-cores, but at the same time, they also guzzle less power. Their whole focus is power efficiency and achieving the best performance per watt. So, what does an E-core actually do? Well, in combination with the P-core configuration, it takes care of multi-core workloads and other kinds of background tasks while leaving P-cores mostly unoccupied for heavier workloads.

On both Intel's 12th-Gen and 13th-Gen chips, E-cores are based on Intel's Gracemont microarchitecture. It's a successor to Tremont, which powers some Pentium Gold and Celeron laptop chips. We're guessing you get the idea of where they're coming from—they're mainly low-power cores running at low clock speeds (as low as 700MHz in some mobile chips). Despite the fact that they're low-power cores, Intel likes to flaunt their performance compared to cores from previous generations.

P-Cores vs. E-Cores: How Do They Work Together?

An Intel CPU

In a nutshell, it works pretty well. According to Intel, the P-cores in 12th-Gen chips provide 19% better performance than the cores on Intel's 11th-Gen chips, with 13th-Gen chips only improving upon this. In addition, Intel E-cores are no slouch, either. They provide 40% better performance at the same power as Skylake chips. The Skylake architecture was launched in 2015, but it's still widely used in some older gaming computers today, so for cores that are supposed to be low-power, that's not bad at all.

With that new hybrid core layout, Intel positioned itself back at the top of the CPU performance game. Not only are they fantastic for gaming, but they're also great for productivity purposes, partly because of the combination of E-cores and P-cores. In that, it doesn't really come down to "performance cores vs. efficiency cores," but rather how well the performance cores and efficiency cores can work in tandem to boost overall performance.

On benchmarks, the new Intel chips are shown to have amazing single-core performance and incredible multi-core scores, showcasing their surprising new-gained versatility. Intel chips were known for their amazing single-core performance but were often scolded for lagging behind AMD in multi-core. That tide changed with its new core layout.

And as we said before, AMD knows it's a winning formula. While Ryzen 7000 came with a layout of all-identical Zen 4 cores, Ryzen 8000 chips, whenever those come out, are rumored to be coming with a similarly hybrid CPU architecture.

Hybrid CPU Layouts Are the Future

While the concept of performance vs. efficiency cores isn't new to the tech world, it is new to the x86 architecture, and Intel is seeing amazing results. As a result, core counts on its chips have increased, and with them, performance.

They're one of the most important developments in PCs in years, even in their initial iteration, and we can't wait to see how they improve in the future.