When it comes to rendering, video editing, and number crunching, more CPU cores is always better, and the best and fastest CPUs have lots of cores. So, if you want the best gaming CPU, you might think you'd want the CPU with the most cores, but it's not that simple. While cores are important for running the latest games, more cores stop mattering after a certain point. Here's what you need to know about games and CPU cores.
The basics of CPU cores
The CPU is basically the brain of a computer, and while the first CPUs came with just a single core, today CPUs almost always come with at least two. For the kind of CPUs you'd find in PCs today, the practical minimum is four cores as AMD doesn't make dual-core CPUs anymore and Intel only rarely makes dual-cores.
Each core or thread in a CPU is capable of working on a task all by itself, which means (in theory) more work can be done with more cores. To that end, CPUs might also have additional logical cores or threads, which is basically a way of dividing up real, physical cores into smaller parts to increase multicore performance. Today, most CPUs have just two threads per core, because more threads per core is harder to implement and doesn't improve performance all that much anyway.
So, more cores and more threads means more performance, though there is a catch: it's difficult to get lots of cores to work on the same thing at the same time. The CPU was invented as a single-core processor after all, and it took decades for companies to start making CPUs with more than one core. Lots of different tasks can be run on a large, multicore CPU without issue, but you can't expect the same CPU to handle a single task super quickly. For games, that's a key limitation.
Games can only use so many cores
The basic problem for games and CPUs is that the software can only use so many cores. Without getting too technical, there's simply a practical limit as to how much work you can dole out to multiple cores. One core will almost universally do a good chunk of the work on its own, and this is just for the latest games. Older games that predate the popularity of mainstream multicore CPUs might even just use a single core, making additional cores totally useless.
Source: AMD
The above chart illustrates how a game's workload might be spread out in a modern DX12 game. The main core up top has the most work to do, and each core down the line has progressively less and less work to do. Eventually you might even get to the point where some cores don't even get to run the game's code and instead are just working on DirectX stuff, which helps the game run but isn't technically part of the game itself.
Now, this chart is pretty old and was created before the first Ryzen chips came out in 2017, but the story really hasn't changed in nearly a decade. Obviously, a CPU with one or two cores will often be outperformed by one with four or six cores, but after that point, there are diminishing or no returns. However, it is true that having more cores will help to run both games and other tasks in the background, like web browsers, videos, streams, and so on. But that's only because, with fewer cores, different applications might have to fight over CPU resources, resulting in congestion and a slow PC.
Realistically, two- and four-core CPUs will probably not be sufficient for the typical gamer unless it's a very recent CPU. If you're using an older two- or four-core, you'll probably need to shut down lots of things or maybe even everything running in the background, and even then you probably won't be able to hit framerates much higher than 60 FPS (though this might not be entirely because of the amount of cores). With six or more cores, there are usually enough resources to go around that you won't see any significant slow-downs.
So what in a CPU makes games perform better?
Source: AMD
If more cores don't really impact gaming performance after the eight-core mark, then why are massive CPUs like the Ryzen 9 7950X and Intel Core i9-13900K some of the fastest? Well, AMD and Intel aren't just charging you for more cores, they're also charging you for higher clock speeds and additional cache, which impact performance in most applications but are especially important for gaming. Games can't use more cores, so the only way to get better performance is individually faster cores with more frequency and cache. Even beefing up cores with more features won't do nearly as much as increasing frequency and cache size.
To that end, some of AMD's best gaming CPUs when it comes to high-end performance use 3D V-Cache, which adds more cache to a CPU. 3D V-Cache actually lowers frequency a bit, but because it adds such a massive amount of cache, it completely offsets the lower clock speed and still increases performance in most games. Intel hasn't yet offered a similar feature for its best CPUs, but its latest 13th-generation chips have much more cache than older 12th-generation models, and Intel CPUs require much less cache overall compared in order to achieve similar performance anyways.
You might also be wondering about per-core or single-threaded performance. For a long time, it was thought that CPUs with beefy cores that had great single-threaded performance were the best for gaming, but this isn't really true. Games simply don't require raw horsepower and don't benefit from newer cores with the latest features. Again, it's clock speed and cache that really improve gaming performance, and although CPUs with a high clock speed tend to have good single-threaded and gaming performance, good or bad single-threaded performance on its own isn't an indication of gaming performance.
Today, you should probably get a six-core CPU even if you're just gaming
The bottom line is that while you can get away with a four-core CPU, you're not going to have a great time in all likelihood. Six cores is ideal, and eight cores will give you plenty of wiggle room. Any more than that will be overkill, unless you're running a ton of stuff in the background that actually requires lots and lots of extra cores.
Today, $100 will get you an older six-core CPU, and while the gaming performance on older CPUs is usually a little poorer than newer chips, you'll usually have an easier time running both a game and background stuff on a last generation six-core than you will on a new four-core. There are lots of great, cheap CPUs out there that'll give you both six or more cores and good gaming performance, so if you're choosing between a brand-new quad-core CPU or a last generation six-core CPU, I'd probably go with the older one with more cores.
