Updated at: 16-05-2023 - By: Leo Hall
The meaning of the terms “CPU bottleneck” and “GPU bottleneck” Here is the most basic and straightforward explanation of these two concepts.

If you’re just getting started with PC gaming and building your first gaming rig, you’ve probably already come across the term “bottlenecking” in your research.

Is there a bottleneck in your current setup, and how do you know if there is one? What is bottlenecking in the context of PC building, and how do you avoid it and fix it? In this article, we’ll discuss all of that and more.

What Is A Bottleneck?

When examined more closely, the term “bottleneck” reveals its meaning. The bottle’s neck is the narrowest part of the bottle before the opening, and it serves to control the flow of the liquid inside by limiting the amount that can flow out.

Now, in the context of computer hardware, a bottleneck is an instance of subpar performance due to one component’s inability to keep up with the others, thereby slowing down the PC’s ability to process data.

Nevertheless, a “bottleneck” can be caused by essentially any component that is noticeably weaker than the other components making up the PC. It’s possible that multiple components are to blame for the sluggish performance, especially if one component is more potent than the others.

What Is CPU and GPU Bottleneck? [Explained] - YouTube

Below, we’ll go into more depth about the most important performance bottlenecks to think about in 2022, which are CPU and GPU bottlenecks.

CPU and GPU Bottleneck

Both the central processing unit (CPU) and the graphics processing unit (GPU) can become bottlenecks in the other’s performance. The number of frames per second you get will decrease.

CPU Bottleneck

One reason why CPU bottlenecks are more common in gaming PCs is that gamers almost always give priority to the GPU, which means they may cut corners elsewhere.

Buying an RTX 2060S instead of a GTX 1660 Ti might mean settling for a less powerful processor, such as an Intel i3-9100, rather than an i5-9600K due to the price difference.

However, the RTX 2060S is beyond the capabilities of a budget CPU like the i3-9100; in fact, even the GTX 1660 Ti would be too much for it to handle. A significant bottleneck would result, with the RTX 2060S operating at around 70% of its maximum capacity due to the CPU’s inability to process data and issue instructions quickly enough.

GPU Bottleneck

However, the converse is also possible. It’s possible that someone, out of ignorance or inexperience, would try to use a low-end graphics processing unit (GPU) with a high-end central processing unit (CPU).

Obviously, if playing games is your main priority, a Ryzen 7 3800X and a GTX 1660 Ti are not the best choices. With a mid-range graphics card like the GTX 1660 Ti, the above-mentioned CPU’s processing power would be largely wasted.

A workstation-first, gaming-second PC might benefit from such a configuration. However, if we are only concerned with gaming, the primary question you should ask about a CPU is whether or not it is fast enough for the GPU you are considering. The graphics processing unit (GPU) is responsible for the bulk of the game’s workload, so a faster CPU won’t improve your frame rate (FPS).

Causes of CPU and GPU Bottleneck

Let’s talk about what actually slows down a central processing unit or graphics processing unit.

In light of what we have talked about so far.

You might blame your computer’s processing speed or your graphics card for the issue.

The games themselves are not the sole cause of CPU or GPU bottlenecking; quite the contrary.

Video games aren’t made to be alike. Games can be either CPU or GPU dependent, depending on the configurations chosen within the game.

Games that rely heavily on the processing power of the CPU typically have a high frame rate but low-resolution visuals. Some examples of such games are:

  • Skylines of Cities
  • Minecraft
  • CIV 5: The Dawn of a New Civilization
  • Black Flag, an Assassin’s Creed Game

GPU-dependent games are those that benefit greatly from a powerful graphics card. Listed below are some of the most GPU-intensive games currently available.

  • Witcher 3: Wild Hunt
  • Last Light on the Metro
  • Battlefield 2
  • Waning Candle

Overall, CPU and GPU bottlenecks can be caused by factors other than the hardware itself.

For this reason, it’s important to tailor your gaming rig selection to your preferred games. If you start with this, you won’t have to “upgrade” your parts for a long time.

How To Check If Your CPU Or GPU Is Causing A Bottleneck

Now that we’ve covered what bottlenecks are, let’s talk about how to tell if your computer has one and what’s causing it. This is not always easy to tell because games can be optimized in different ways, and some may place greater demands on the CPU than others.

The MSI Afterburner, Asus GPU Tweak, AMD Control Center, or another overclocking utility can be used to check this, among other things.

Check the CPU and GPU loads when the PC is under heavy load, such as when playing a demanding game. If your GPU is not being taxed to its limits, but your CPU is, the CPU is the limiting factor. On the other hand, if the graphics processing unit (GPU) is working at full capacity while the central processing unit (CPU) is at a much lower percentage, then the bottleneck is in the GPU.

The difference in workload between the central processing unit and the graphics processing unit should also be considered. For example, if your CPU is working at full power while your GPU is relaxing at a more comfortable 70%, you’re missing out on a good chunk of performance; however, if both components are operating at around 90%, it’s a small bottleneck and not a big deal.

Another option is to use a bottleneck calculator, where you can enter the exact model numbers of the CPU and GPU you plan to use, as well as the total amount of RAM you intend to install. It is a helpful tool when constructing a personal computer because it estimates the bottleneck percentage.

Now, it’s important to remember that no system is completely bottleneck-free because one of the two parts is always going to be a little faster. A bottleneck of up to 10% is typically not a problem, but anything above that may indicate that some configuration changes would yield better results.

How To Fix CPU and GPU Bottlenecks

Given the foregoing, the only way to prevent major bottlenecks is to prepare in advance and check that all of your parts are playing on the same team.

If you discover a major bottleneck in your computer where none existed before, you will need to either upgrade the underperforming part or downgrade the overperforming part to fix the problem.

Why CPU bottlenecks are more complicated- and arguably more important

The real bottleneck is always going to be your CPU. The visual flair you see on your screen is the work of your graphics card. The central processing unit is responsible for all the heavy lifting, such as keeping track of where players and objects are at all times and performing the countless other calculations needed for smooth, real-time gameplay. The CPU, not the GPU, handles all of the in-game processing.

Remember this short summary of our argument:

The maximum framerate is set by the CPU, while the maximum visual quality is set by the graphics processing unit.

Many independent studies have found that, provided your monitor’s refresh rate can keep up, higher framerates result in a more fluid experience and improved gameplay.

Other bottlenecks to think about

The central processing unit and the graphics processing unit aren’t the only potential sources of slowdown. There’s also the fact that…

Memory Bottlenecks

Crashing due to insufficient memory! This also serves as a bottleneck for the CPU in a technical sense.

If you’re using an AMD Ryzen processor, the speed of your RAM has a direct impact on its performance. Users not purchasing the highest quality gaming RAM is not the primary reason for RAM speed’s negative impact on performance, though.

The problem is that most users are still employing single-channel RAM configurations rather than the more efficient dual- or quad-channel layouts.

RAM that is “single-channel” is RAM that can only operate at 50% of its maximum speed because it is only using one stick.

Running two RAM sticks side by side is what gives “dual-channel” RAM its ability to reach its stated speeds, hence the name.

“Quad-channel” RAM means using four individual RAM modules, or sticks, in a single memory channel. Although not as beneficial as dual-channel, it still improves performance and could be the best option for any applications that heavily rely on RAM speed.

Running in dual or quad-channel makes little difference for gaming. However, you should not be operating in single-channel, as this will significantly reduce the effective speed of your CPU (especially with Ryzen!) and cause you to receive less than the advertised performance.

Running your RAM in dual channel is essential if you care about maximizing performance and preventing CPU bottlenecks.

Storage Bottlenecks

Unless you have slow or old hard drives, you probably don’t need to worry about storage bottlenecks.

A 7200 RPM HDD that you’ve had for a year or two should work just fine. As long as there are no hiccups when loading assets or anything else, you should be fine, even though load times won’t be as fast as they would be with an SSD.

Older or slower than 5400 RPM HDDs are where you’ll run into trouble. When they start to break down, games may have trouble loading all of their textures and assets. In extreme cases (like with Overwatch), you may not be able to load the map in time to join the game if your drive speed is too slow.

If you’re serious about your gaming, an SSD is a must-have.

CPU Bottleneck vs GPU Bottleneck | Which one is BAD? Which one is GOOD?  (ft. Ryzen 4000) - YouTube

How to avoid CPU bottlenecks in your next PC build

Now that we’ve covered everything, how do you prevent future instances of the CPU becoming a bottleneck?

We’ll keep this brief PC building guide simple by focusing on just a few key points. If you stick to these guidelines, you should be fine:

  • Don’t skimp on the processor. Do not buy a GPU that costs several times as much as your CPU. Compared to CPUs, graphics processing units (GPUs) are more affordable and easier to upgrade in the future. Upgrade your CPU now, and your GPU tomorrow.
  • A modern AMD Ryzen 5 or Intel Core i5 processor, for example, should do the trick if you’re looking for a CPU with good single-core performance. If you want the best single-core performance from either manufacturer, you should use the most recent architecture. Intel has a slight edge at the moment of writing; if you can afford it and want to push ultra-high frame rates (150 ) in cutting-edge games, you may want to go with them.
  • Invest in a dual-channel RAM kit, especially if you’re using Ryzen, to avoid bottlenecking your CPU.
  • Invest in a solid-state drive (SSD) if you want faster load times and better in-game texture and asset loading without putting undue strain on your CPU or GPU.

The Best CPU GPU Combos for Gaming (2022)

Types of Games You Play (CPU Intensive?)

Some games put more demand on the central processing unit than others, so a given CPU GPU pairing may result in a CPU bottleneck in one game but not another. Games that require a lot of processing power from the central processing unit (CPU) often have large game worlds, a large number of in-game objects/characters/units needing processing (think strategy games), a large amount of complex physics or artificial intelligence, and so on.

In contrast to the standard practice of allocating a larger portion of your budget to the graphics processing unit (GPU) than the central processing unit (CPU), you may want to allocate a more balanced portion of your budget to both components if you’re building a PC for a specific game (or genre) that turns out to be CPU intensive, like GTA V. Monitor resolution and, more importantly, refresh rate (which I’ll get into shortly) influence how much emphasis is placed on the central processing unit.

Many games, including No Man’s Sky, Warzone (especially in PvP and on a 144 Hz monitor), Boneworks VR, Civilization V, Escape from Tarkov, World of Warcraft (especially in raids, dungeons, and major cities), Watch Dogs Legion, the majority of the Assassin’s Creed games, and Cyberpunk 2077, require a powerful computer to run smoothly. If you’re interested in games that require a lot of processing power, check out this complete list.

A game may be CPU intensive, but it may also be GPU intensive, so don’t assume that because it uses a lot of CPU power that it doesn’t need a powerful graphics processing unit. Even if your game(s) is/are extremely CPU intensive, you may still want to invest more heavily in your GPU as opposed to the CPU if you intend to play at higher resolutions. Perhaps; that is the million dollar question.

Minecraft, League of Legends, StarCraft 2, and Counter-Strike: Global Offensive are just a few examples of CPU-intensive games that can get by with less powerful graphics processing units. Besides specific use cases like running Minecraft with powerful graphical mods like shaders, these are examples where the CPU is demonstrably more important than the GPU, and where you can get away with an average GPU if your CPU is good (and where, especially at 1080p, this may indeed be the optimal setup to go for).

Your Screen Resolution (1080p, 1440p, 4K/VR?)

CPU bottlenecks can be avoided or reduced by carefully considering not only the games you play, but also the resolution at which you play. Or, more precisely, how many frames per second you can expect. The graphics processing unit (GPU) is taxed more heavily at higher resolutions because more pixels must be rendered. The CPU is less likely to be taxed at higher resolutions, but this is not directly attributable to the increase in pixel density. Let me elaborate.

Whether you’re playing at 1080p or 4K resolution, the CPU still has to process the same number of calculations (physics, AI, collisions, character positioning, hits, etc.) in order to prepare a frame to be rendered by the GPU.

Although the frame rate will be lower at higher resolutions, the CPU usage may actually decrease because it is processing and preparing fewer frames as opposed to lower resolutions where you get higher frame rates (and thus the CPU has to process more frames). You could therefore say that the screen resolution has an indirect effect on the amount of CPU a game uses.

By switching resolutions and keeping an eye on how they affect your CPU usage (with a program like MSI Afterburner), you can see for yourself the correlation between the two.

Since higher resolutions result in lower frame rates, the CPU is relieved of some of its workload.

Lower resolutions mean less work for the GPU, which means more work for the CPU because of increased frame rates.

Your Screen Refresh Rate (60Hz, 144Hz, 240Hz?)

When deciding on a central processing unit (CPU) and graphics processing unit (GPU) for gaming, the refresh rate of your monitor is also an important factor. In fact, it’s arguably the single most crucial consideration when determining which CPU to use. When compared to the old standard of 60Hz (which only allows up to 60FPS), higher refresh rates like 144Hz or 240Hz allow for significantly higher frame rates.

However, a more powerful CPU is required to achieve frame rates of 144 or 240, and to maintain those rates consistently so that they do not drop too far below during intense moments of action. In particular, games that rely heavily on the CPU benefit from playing at 1080p resolution (where GPU usage drops and CPU usage rises because frame rates are higher than at 1440p or 4K) and vice versa.

High-refresh-rate, high-resolution screens have the same problem, necessitating a more powerful central processing unit. While the GPU is more crucial at 1440p than 1080p, reaching 144FPS still requires a good CPU, making 1440p 144Hz monitors more demanding on the CPU than 1440p 60Hz monitors.

Best CPU GPU Combos in 2022 (Avoid Bottlenecks in Most Games)

Let’s get into the nitty-gritty of picking the optimal CPU and GPU for the most common screen sizes and refresh rates. Listed below are some suggestions for well-balanced CPU/GPU setups that should work well for most games without experiencing CPU bottlenecks.

Remember that these are just suggestions for what kinds of central processing unit and graphics processing unit work well together. Please keep the following in mind:

  • Similarly, if you play games with higher than average graphics processing unit (GPU) requirements (for which you may want a better GPU than listed below), you may need to adjust your choice of CPU.
  • These suggestions are for the performance-oriented gamer who wants the best possible gaming experience. If you don’t need to hit the “flawless” targets of 60FPS, 144FPS, etc., then you can save money or get parts that are slightly less powerful and still have a very smooth experience for any given resolution and refresh rate below.
  • You may want to dig deeper into the specifics of a game’s system requirements and benchmarks if you’re building a PC for that game in particular (check out our past guides for more information).
  • Your CPU (and RAM) needs may be higher if you’re building a PC for gaming and streaming to Twitch at the same time, using your PC for CPU-heavy work, or like to have a ton of apps running in the background while gaming.
  • Since a CPU that can handle 60 or 144 FPS at 1080p can also handle those same numbers at 1440p or 4K, the recommendations for those resolutions are identical. Since virtual reality headsets typically have higher refresh rates (80Hz, 90Hz, or 120Hz), and since choppy frame rates are much more noticeable and unpleasant in VR, the recommended CPU specifications below are slightly more powerful for PC VR headset gaming. Additionally, many mainstream VR titles have marginally higher CPU requirements than non-VR counterparts.
  • Keep in mind that some Intel CPUs, like the 12600KF and 10400F, also come in an “F” version. There is no difference between the 12600K and the 12600KF, other than the fact that the latter has an integrated graphics chip and the former does not. If you don’t need integrated graphics (which is most gamers since you’ll probably be using a dedicated graphics card), these “F” models can be a good way to save money without sacrificing performance.

1080p (1920 x 1080)

Recommended CPU/GPU for 1080p/60 FPS Gaming

Pricing: i3-10100, Ryzen-3-3100, Ryzen-3-3300X, and GTX-1650/GTX-1660/RTX-3050/RX-5500/RX-5600 XT/XTX

Recommended Processors: i3-12100, i5-10400, Ryzen 5-3600, and RTX 3060, RTX 2060 Super, RX 6600, and RX 5700 Graphics Cards

Optimal CPU/GPU Setup for 144Hz Play at 1080p

Intel Core i3-1200, Intel Core i5-10400, AMD Ryzen 5-3600 RTX 3060, RTX 2060 Super, Radeon RX 6600, Radeon RX 5700, Value

i5-12400, i5-12600K, Ryzen 5-5600X, RX 6600 XT, RX 5700 XT, RTX 3060 Ti, RTX 2070 Super are the best components you can get.

Best: Core i7 12700K or Ryzen 7 5800X with an RTX 3070, RTX 3070 Ti, RTX 2080 Super, Radeon RX 6800, or Radeon RX 6700 XT

The Top CPU/GPU for 1080p at 240/360 FPS

Cost-effectiveness: Core i7-12700K/Ryzen 7-5800X with GeForce RTX 3070/3070 Ti/RTX 3080/RTX 2080 Super/RX 6800/RX 6800 XT

i9 12900K / Ryzen 9 5900X RTX 3090 / 3080 Ti / RX 6900 XT (Pro)

1440p (2560 x 1440)

CPU/GPU Settings Optimized for 1440p at 60 FPS

For the money, go with: i3-10100, Ryzen-3-3100, Ryzen-3-3300X , RX-6600 XT, RX-5700 XT, RTX-3060 Ti, RTX-2070 Super.

i3-12100, i5-10400, or Ryzen 5-3600 with an RTX 3070, RTX 2080 Super, RX 6700 XT, or RX 6800 is recommended.

For 1440p at 144Hz, the Best CPU/GPU Combo Is…

Intel Core i3-1200, Intel Core i5-10400, Ryzen 5-3600, Radeon RX 6800, Radeon RTX 3070, Radeon RTX 3070 Ti, Radeon RTX 2080 Super

Recommended Specifications: i5 12400, i5 12600K, Ryzen 5 5600X, and RX 6800 XT with RTX 3080 or RTX 3080 Ti

Can Motherboard Bottleneck GPU? [Beginners Guide 2022]

4K (3840 x 2160)

CPU/GPU Settings Optimized for 4K 60 FPS Gaming

Pricing: i3-10100, Ryzen-3-3100, Ryzen-3-3300X, plus RTX-3070, RTX-3070 Ti, RTX-2080 Super, RX-6700 XT, RX-6800

CPU: i3 12100, i5 10400, or Ryzen 5 3600; GPU: RTX 3080 or RX 6800 XT

The Ultimate CPU/GPU Setup for 4K 144Hz Gaming

Pricing: RTX 3080/RX 6800 XT i3-12100/i5-10400/Ryzen 5-3600

CPU: i5 12400/i5 12600K GPU: NVIDIA GeForce RTX 3090/AMD Radeon RX 6900 XT

VR (Virtual Reality)

Best CPU/GPU for Virtual Reality Play

Intel Core i3-12100, Intel Core i5-10400, AMD Ryzen 3-3300X, AMD Ryzen 5-3600, plus GeForce RTX 3060, GeForce RTX 3060 Ti, Radeon RX 6600 XT, or Radeon RX 6700 XT, all at a reasonable price

The best configuration includes an Intel Core i5-12400 or i5-12600K processor and a Nvidia GeForce RTX 3070, RTX 3080, RTX 3080 Ti, or a Radeon RX 6800 or RX 6800 XT graphics card.

The pinnacle: an Intel Core i7-12700K or Core i9-12900K processor with a Radeon RX 3090 or RX 6900 XT graphics card.

Conclusion

That wraps up our brief description of bottlenecks, the various kinds there are, how to tell if your computer has a significant bottleneck, and what to do if it does.

Feel free to refer back to this article for reference as you build your new PC or implement upgrades to your existing setup.