Choosing between a mid-level 6-core CPU and a higher-level 8-core CPU is not a simple matter of more cores equals better performance. In fact, it's a subtle decision that you have to make after considering four main factors. Here's how it works. I mean, more cores means better gaming, right? Not necessarily.
Just five years ago, debating the merits of a 6-core CPU versus an 8-core model wasn't possible. We were all stuck with 4-core chips at the consumer level - to break through that barrier, we had to pay big bucks for a high-end desktop ("big socket"). And you don't have to go to an extreme to play the game.
Nowadays, game developers have started to adapt to the new normal of high-core processors. And if you're going to have a PC for the next few years, you'll want one that will comfortably keep up with you for the duration, at all levels
Cyberpunk 2077 is an example of an open world game that makes use of multi-core processors, scaling performance up to eight cores. Core count does not tell the whole performance story. The games you play and the resolution at which you play them also influence the real world result. In games that do not take advantage of multi-core processors, single core performance is more important. You will often see negligible differences in framerates between 6-core and 8-core processors of the same generation.
Other games - think blockbuster-level games, especially those with 'open world' environments - make more use of available cores, sometimes even scaling performance with core count. Benchmark results for CPUs with lower core counts can start to trail their high-end brethren, and in some games, you may see a 10-15% difference between 6-core and 8-core processors.
However, you can't assume that you should pick the 8-core processor and call it a day if you're a fan of big open-world games. For a family of CPUs, we might see the performance of the 6-core processor outperform the 8-core version in a specific title.
You also won't see as much difference the higher the resolution. We can get to 1080p, and the performance gaps shrink to virtually zero by getting to 1440p, in some games. 4K range is the heaviest is usually and entirely on the video card. In the end, you'll have the clearest picture on the chips you're comparing after looking at specific test results.
Some people believe that since gaming consoles have 8-core processors, PC users should expect eight cores to become the standard for gaming. But while games have started using more of the available cores, we don't believe that will happen anytime soon. And when it does, your gaming PC will be ready for an upgrade anyway.
Consoles are built for a long life: the last two generations have lasted about seven years each. The eight cores in the PlayStation 5 and Xbox X and S series will likely have to last the same amount of time - which is almost double the average lifespan of a gaming PC. A current-generation 6-core processor should run well for another four to five years, which is when most PC gamers start thinking about an upgrade. On the other hand, if you plan on making big gains with your processor, an 8-core chip hedges your bets. Many people kept the Core i5-2500K and Core i7-2600K for eight years or more before finally upgrading.
When it comes to value, the lower price of a 6-core processor is hard to beat. The less you spend on a component, the more money you'll have for gaming. For some people, a constant gaming 'diet' is just as important as framerates - or even more so. Unsurprisingly, a 6-core purchase costs less money. As a 'mid-range' processor, these CPUs cost between $200 and $250. Moving up to an 8-core processor will cost between $330 and $360.
This characterization oversimplifies the current market, but you can still have confidence that 6-core chips will cost less than their 8-core counterparts of the same era. You'll save between $100 and $160, or almost three blockbuster games at full price.
That's an immediate price win. Another potential is if 6-core processors remain the baseline for the distant future. If you upgrade at the same point you would have with an 8-core processor, you won't spend more on your CPU unnecessarily. But if you find out later that you have to upgrade sooner than expected? You'll also see an increase in performance after the hardware upgrade. And depending on advances in technology, you might even spend less than you assume - so no money is wasted.
This factor comes into play when deciding between an AMD processor and its rival Intel. For a long time, AMD has kept the same socket motherboard between generations of Ryzen CPUs. This allows owners of earlier Ryzen chips to keep their existing motherboards, making processor upgrades very easy and much cheaper. In contrast, Intel changes its socket specifications much more frequently (usually within two generations), almost guaranteeing a CPU and motherboard upgrade. But when putting two chips from current AMD and Intel generations together, this point is irrelevant. AMD is moving to the AM5 socket with the Zen 4 processors, negating that upgradeability advantage for its existing Zen 3 (Ryzen 5000 series) processors. If you buy a Ryzen processor today, upgrades to a future Zen chip will require a new CPU and motherboard, like an Intel.
However, if you're on a budget and comparing an older generation of processors, you may find that a 6-core AMD part offers more value than an 8-core Intel part from the same era. Shop the used market later for a new AMD CPU compatible with socket AM4 in the future (maybe even an 8-core one), and you'll improve your PC's performance while keeping your costs down.
Unlike other direct matchups, this showdown results in few specific winners for our categories. The problem with arguing about CPU core count and how they affect PC gaming is that processors don't live in a vacuum. Not only does a processor's microarchitecture affect performance and upgradeability, but a gamer's budget influences what prices will be feasible and how long a CPU will stay on your computer. (And let's be realistic here: if you're debating between a 6-core and 8-core Processor, your budget matters.)
In the end, you should research specific 6-core and 8-core chips to see what kind of performance you get, and then balance that against your budget and plans for the future. But if you're really busy and want to find a champion, then here's the judges' decision: Buy the 6-core for gaming. You can buy the 8-core if you want, but not for gaming - you should have other things you plan to do with it that make use of those extra cores.
Now go build your PC, load the next game, and have fun!