A poorly matched CPU and GPU can seriously impact your PC’s performance and should be avoided.
Selecting compatible PC components such as motherboard and processor is critical as you may encounter instability issues or hardware damage. When purchasing a new PC, matching the right CPU with the right GPU is equally important. If you do this step incorrectly, you can lose a lot of system potential on both sides. If the GPU is too good for the CPU (pairing an Nvidia GeForce RTX 4090 with an Intel Core i3 processor) or vice versa, you’ll disable some in-game settings and enjoy a subpar experience.
What is the CPU and GPU bottleneck?
How specific components affect performance
A system bottleneck is when a component is not powerful enough to handle the rest of the PC. This usually affects a single component, such as the graphics card, drive, or even processor. An exaggerated example of this is the one used above, where we paired the i3-13100F with an RTX 4090, resulting in a serious CPU bottleneck. GPU bottleneck would occur if the GPU was much slower than the CPU, such as the Core i9-13900K paired with an RTX 2060.
In an ideal world, there should be no bottlenecks between your CPU and GPU, and both should be equally fast so you can get the most out of your computer. But this isn’t really possible, mainly because there’s hardly any task that will equally max out both your CPU and GPU, except perhaps a benchmarking application or stress test. Some programs use the CPU more, while others rely on the GPU to do most of the work. Therefore, even if you use the most suitable CPU and GPU, one will always limit the other to some extent in different applications. Since these games have simple graphics, any modern mid-range GPU will easily be able to achieve frame rates of 200 or more. If money is no object, just choose the best GPU and the best CPU you can buy. That way, you won’t have to worry about the bottleneck because you’ll be using the fastest consumer CPU and GPU available, and a faster upgrade component doesn’t yet exist. Keep in mind that according to the bottleneck definition, even these will have some degree of bottleneck in every use case. But the bottleneck will be minor and won’t hold your computer back too much.
But for everyone else, you should always know what you plan to use your computer for before choosing its components, as this is where exceptions come into play. Depending on what you end up using your computer for, your bottlenecks may be high or low and may alternate from one component to the next.
Which is better for gaming?
The GPU is (usually) the most important component
Rendering huge 3D worlds typically requires much more effort from the GPU than from the CPU. The majority of the time spent rendering a single frame of a video game is spent on the GPU, with only a small portion of it used by the CPU to perform physical or logical calculations. Therefore, both the CPU and GPU determine the maximum frame rate of a game, but unlike the CPU, the GPU is also heavily influenced by the resolution and graphical quality of the game.
Let’s explain this with an example. Resident Evil 4 Remake is a superbly optimized game. To get 60fps at 1080p in this game at low-medium graphics settings, you’ll need a mid-range CPU and GPU like an Intel Core i5 and GTX 1050ti. But the same game running at 4K, 60fps, on ultra settings with ray tracing enabled, will require a much more powerful GPU like an RTX 3080, but won’t require a CPU upgrade. While an RTX 3080 paired with an Intel Core i5 may look silly, in this game the processor easily manages 60 frames, which is what we’re aiming for, and the increased resolution and graphics settings only put extra strain on the GPU, not the CPU.
Both the CPU and GPU determine the maximum frame rate of a game, but unlike the CPU, the GPU is also heavily influenced by the resolution and graphical quality of the game.
Therefore, to run high-quality single-player games with
With high resolutions and graphics settings, having a powerful GPU becomes much more important. And if, in addition, you need high frame rates, you will have to invest in both the CPU and the GPU, since the frame rate depends on both of them. But not all games run as well as Resident Evil 4 Remake, and most modern AAA games aren’t even very well optimized at launch, resulting in games that are more CPU-intensive.
Games that have a lot of moving parts or a lot of logic or simulation, such as Assassin’s Creed Odyssey, Star Citizen, X4: Foundations, or most RTS games, can often bring low- and mid-range processors to their knees. Likewise, trying to reach frame rates over 200 in older games or competitive first-person shooters with relatively simple graphics, such as Valorant or Rainbow Six Seige, becomes more taxing on your processor than if it were running at 60 or 60 frames. more. even 120.
So, for a gaming PC, it’s important to consider the resolution and frame rate of your games, as well as the type of games you’ll be running on it, before settling on the CPU and GPU. However, keep in mind that even if you can save some money by buying a relatively weak GPU or CPU that performs well for your use case, this will limit you in the future from playing other types of games where the weak component will cause a bottleneck.
Performance
What you need to get the job done
Most productivity-related apps and tasks use the CPU more than the GPU. Things like running spreadsheets, Adobe applications, programming software, web browsers, and virtualization applications have a direct impact on your processor. To get the best performance from them, you’ll need a powerful CPU, but even a weak GPU will suffice.
In 3D rendering software, both the CPU and GPU are equally important, so you can’t skimp on either one. Likewise, video editing and data analysis software also uses both of these components, so you will need a powerful CPU and GPU to get the best performance.
How to calculate a bottleneck
Find the source of productivity loss
Although this is considered a very rough estimate, any online bottleneck calculator can come in handy sometimes.
Go to the bottleneck calculator website.
Select the CPU and GPU you plan to purchase.
Select the screen resolution of the monitor on which you want to run these components.
Select the type of tasks you’re likely to perform on this computer and click Calculate.
The results will show you the percentage of bottlenecks that one component will cause to another. Anything below 5% is a good match.
An even better way to check for bottlenecks in your chosen components is to go to YouTube and watch test videos. Just enter the name of your components and the app or game you want to test, and you’ll likely get a video that shows how well both components fit together. Try watching a few videos to get more reliable information.
Dealing with the bottleneck
Maybe it’s time for an update
If after the build you find that your computer is bottlenecked in your use case, there is nothing you can do about it except upgrade. Keep in mind that upgrading your GPU is quite simple: you just need to plug in a new, faster graphics card and you’re good to go. But for the processor, if you’re upgrading to a newer generation with a different socket, you’ll also have to buy a new motherboard and may even need to upgrade your RAM from DDR4 to DDR5.
Even if you upgrade your processor from the same generation, the process of replacing the CPU will still be much more tedious than replacing the GPU. Therefore, it is always a good idea to future-proof your processor to some extent if possible, to save yourself the hassle of upgrading it later.