Hardware Bottleneck: What Is It and How To Avoid It?

The beauty of desktop computers is how each and every build can be personalized since you get to pick the different parts or components. It’s like LEGO except it will make you go broke faster (these days, at least). But as happy as this hobby seems for tinkerers and enthusiasts, there is one somewhat common pitfall that everyone is vigilant about: hardware bottleneck.

For many, it’s a severe limitation in a hobby that could otherwise make you feel like McGuyver or some mad inventor who built some dark horse or underdog computer for gaming. We’ll be defining hardware bottleneck in its simplest form and also giving you some tips on how to avoid it in the future.

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What Is Hardware Bottleneck?

A bottleneck, simply put, is a component that limits the potential of another component by being less powerful or older. We’ll start with an analogy.

Imagine you have a bicycle and you want to purchase some upgrades for it. Being excited and giddy about your new hobby, you thought of something borderline deranged: what if I hook up a Ducati V4 engine with nitrous to the bicycle? So I won’t have to pedal those deadly uphill climbs.

Well, you can try it, but it won’t work as well as you think because your speed will still be limited by the integrity of the bike’s wheels and chain. At best, you can merely strap an e-motor on your bicycle and turn it into an e-bike.

That’s how hardware bottleneck works. The same logic applies to PCs though to a less exaggerated extent.

You Shouldn’t Pair Powerful Hardware With Weaker Hardware

The most common pairing that introduces a hardware bottleneck to your computer is an outdated CPU/processor with a newer and more powerful GPU/graphics card. 

Such is the case for a lot of gaming PCs because it’s generally known in the community and hobby that the GPU is the most important component for gaming. That’s why when people upgrade their components, they mostly target the GPU first, leaving some components behind.

In other cases, that could also be an aggressive attempt to cut costs for a build. CPUs are still pricey components, after all. So it’s not unheard of for a build consisting of an i3 or Ryzen 3 CPU paired with a high-end 70, 80, or even 90-tier GPU.

Technically, there’s nothing stopping you from committing to that kind of configuration. However, you will have to live with the fact that your GPU will not be performing to its maximum potential because it’s being held back by the CPU. Or vice versa, depending on the build.

So while you did manage to scrimp some savings by pairing a weaker component with a significantly more powerful component, you also somehow wasted money since you’re using a product that doesn’t perform as well as advertised.

For example, that bottlenecked system with an RTX 4080 and an i3 processor will only yield 85 FPS in a certain game; meanwhile, the same system with the same GPU but an i7 or i9 processor will yield 100 FPS or more in the same game. That can be a big difference in smoothness or playability depending on the game.

How To Know if There’s a Hardware Bottleneck?

Thankfully, knowing the extent of a hardware bottleneck for specific configurations is now easier than ever. Back in the 2010s, we all had to perform a bit of guesswork and some internet flame wars to determine the existence of a hardware bottleneck; but these days, there are online tools that can give you an estimate if ‌there’s a bottleneck or not and if so, how bad is it?

A website called PC-Builds has a tool called Bottleneck Calculator where you can form up a config or build and then have the hardware bottleneck calculated. We’ll have to give you a fair warning though, this tool is just an estimate and there’s really no accurate way to determine the bottleneck. Certain CPUs like the 13600K or the 7800X3D are misrepresented on the website, so take the results with a grain of salt. 

In any case, this hardware bottleneck for the PC is calculated by percentages. There’s a percentage for how much of the CPU will be used and a percentage for how much of the GPU will be used depending on the resolution and the intensity of the task. The usage percentage of the component with the lower score will then be subtracted to 100 percent and will then be the bottleneck indicator.

Any value above five percent whether it’s CPU or GPU is considered a bottleneck. The website thankfully presents some solutions which usually just involve lowering or increasing the resolution though this is not really an ideal practice to reduce bottleneck as either image quality or framerate might suffer. 

You’ll also have to factor in the game’s resolution in estimating the bottleneck. Lower resolutions– 1080p and below will tax the CPU more while higher resolutions– above 1080p will tax the GPU more and bottlenecks can change depending on the resolution or task.

Also, it’s important to note that even if there is no bottleneck, it’s not a guarantee of a high framerate. Bottleneck is a different metric altogether and only determines the maximum potential of a config or component, not its gaming performance.

There’s a Rule of Thumb

Now, some bottleneck calculator results are sketchy or just plain inaccurate especially with newer hardware, so you’ll have to trust your judgment based on the typical rule of thumb when determining bottlenecks.

You’ll just have to keep your build and components balanced. For components (mainly CPU and GPU), pair high-end with only high-end , mid-range with mid-range, and so on. You can determine which is which using our handy guide for PC specs (it’s for laptops, actually; but the same logic and naming schemes apply).

And to a certain extent, do note that your system will usually always have a bottleneck. So if you must choose which bottleneck to live with, make sure it’s the GPU that’s causing the bottleneck because it’s easier to upgrade.

How Do You Avoid Hardware Bottleneck?

It starts as early as conceptualizing the build. In conjunction with the website we referred to you as well as the rule of thumb, you can build a system that has minimal bottleneck where the CPU and the GPU are both working near their max utilizations (though this can change depending on the task).

It’s also worth noting that bottleneck issues are not just limited to desktop PCs, but also laptops. Laptop manufacturers will sometimes introduce configurations that are obvious bottlenecks such as an i7 paired with an RTX 3050 (though this is more acceptable as a bottleneck). 

The worst part is that you can’t upgrade a laptop’s CPU and GPU so you’ll have to be more careful and more vigilant in determining whether a laptop has a hardware bottleneck. This way, you can even determine whether a gaming laptop is a good deal or not, simply based on how balanced its hardware combination is; more than anything, knowing a thing or two about a hardware bottleneck helps you get what you or your loved ones paid for.

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