Bottleneck calculators: what are they for?

Pre-built PCs are usually designed to be balanced, but if you’re upgrading or building your system, you might want to be careful when selecting your components to avoid PC bottlenecks. One way to help you with this task is with a reliable bottleneck calculator.

What is a PC bottleneck?

PC bottleneck occurs when the components of your PC do not complement each other, which prevents a certain PC hardware from reaching its full potential because the other simply cannot keep up. In a way, think about having hundreds of entries at once, but you’re only able to process ten at a certain unit of time.

Before diving deeper into the true purpose of bottleneck calculators, it is important to first understand what a bottleneck phenomenon is. It happens when your PC components don’t complement each other, causing one PC hardware to not reach its full potential because the other simply can’t keep up. In a way, think about having hundreds of entries at once, but you’re only able to process ten at a certain unit of time. This can happen to different components of a PC. Yet the best way to illustrate the effect of a bottleneck is through the uneven performance of a graphics processing unit (GPU) and a central processing unit (CPU).

The processor is responsible for the running calculations of audio, netcode, physics, position data, etc. Most notably, it sends the graphics card’s rendering instructions, textures to shaders, and other image data needed to produce pleasing screen visuals. Now, if the GPU was executing those instructions faster than the CPU was passing instructions, that means the graphics card would be resting just before another set of instructions arrives. The downside is that the GPU would render fewer frames per second. On the other hand, if the CPU sent instructions faster than the GPU could, your PC would still experience poor performance. A good example is the combination of the Intel Core i9 gaming processor and the GeForce RTX 3090 GPU, which can significantly unbalance PC performance.

Such examples conclude to the bottleneck of the PC and the importance of components that complement each other. Having the right balance between these hardware components will encourage good PC performance while preventing each part from getting in the way of each other to perform to its full potential.

What is a bottleneck calculator?

When building or upgrading a computer, finding the right hardware formulation can be difficult. As stated earlier, you need parts that complement each other to ensure that the whole system will work in the best possible way. This is important, especially if you want to have a great gaming PC. However, physically testing parts is next to impossible for everyone. Just imagine the cost and effort you would incur if you had to test graphics cards or processors individually in a real-world scenario. The perfect answer for this is bottleneck calculators which will calculate the bottleneck percentage within your system.

This type of calculator comes in handy when you need to analyze the performance of your computer system. By showing you the calculations or the bottleneck percentage, you will be able to determine how the parts work together and identify which part of the computer is slowing it down. This way you can also indicate the things you can improve.

Online bottleneck calculators come in different forms, but they all do the same job of calculating the bottleneck percentage between pieces of hardware. They will ask you to name or identify chips from a specific manufacturer (e.g. Intel or AMD), cores, etc. Some will also give you drop-down options to easily find the hardware you’re hoping to compare.

When using them, it is generally considered that anything above 10% is already a bottleneck. For example, the NVIDIA GeForce GTX 970 and the Intel I5-8600 K have a bottleneck percentage of 14.3%, mainly caused by the GPU.

Online bottleneck calculators

You will find many bottleneck calculators online. Although they differ in some respects, they will give you the service of calculating bottleneck percentages between matched pieces of PC hardware. Here are some of the best-known suggestions we can share:

PC Builds Bottleneck Calculator

Screenshot of PC Builds Bottleneck Calculator

PC Build’s calculator is quite simple and easy to use. Upon entering the page, you will be asked which processor and graphics card you want to compare. You can enter their details in the search bar and suggestions will appear. Simply select the one that matches your search. You will also be asked for the PC’s screen resolution (width and height) and the purpose of the comparison (for example, general tasks, CPU intensive tasks, or graphics card intensive tasks). It will then calculate the percentage for you.

The good thing about this calculator is that it presents not only the percentage, but also information about the perfect compatibility of components in specific situations. It will also tell you if it makes sense to upgrade or not.

Bottleneck Calculator

Bottleneck Calculator

The Bottlenecked Calculator is one of the most popular online calculators out there, but surprisingly, it’s not as perfect as the others we have on this list. When we tested it, it showed inconsistencies in results, mostly due to bugs on its website. Nevertheless, its use is as intuitive as that on PC Builds.

Just identify the graphics card manufacturer here and select the specific model you are looking for. You will also be asked for your PC’s RAM, screen resolution, CPU, and storage. Once you have met the conditions, you can select the Submit button and the Reveal button to see the results. Along with the bottleneck percentage information, it will also show where the problem occurs, suggested replacement, and the bottleneck percentage that will be removed if you apply such changes.

Agent CPU Bottleneck Calculator

Agent CPU Bottleneck Calculator

This CPU Agent calculator is like no other. You will need to enter the CPU, GPU, RAM size, RAM speed, resolution and quality settings. Clicking on the respective boxes for said components will give you a drop-down selection for choices, and there are even prices for each, giving you an idea of ​​how much you’d be spending if you decided to go for hardware upgrades.

The result that this calculator can present, however, is the main highlight. Apart from the bottleneck percentage, it will also show you the CPU and GPU specs. Additionally, it will give you a deeper insight into benchmark-based streaming analysis of 9 games, such as Shadow of the Tomb Raider, Forza Horizon 4, Call of Duty Modern Warfare, Battlefield V, and more. Overall, this is one of the best bottleneck calculators that will present you with the complete set of information you need.

Are bottleneck calculators accurate? Can I trust them?

Bottleneck calculators make your life easier by determining the bottleneck percentage between CPU and GPU, but you should not trust all the information they will provide. They are not accurate at all times, and some are even designed to help their creators monetize them. For example, some calculators will show you suggested materials with affiliate links. This means that buying them will help them earn commissions, so some online calculators will give you upgrade recommendations although they are not necessary.

As such, you need to know your main goal to measure the bottleneck percentage of your PC system. Suppose you are building or upgrading a computer for gaming and other demanding tasks. In this case, you might want to consider the calculator’s suggestions, but be sure to do some extra research to make sure you’re making the right decisions. But upgrading to a bigger, more powerful CPU or GPU doesn’t make sense if your goal is just for general tasks.

On the other hand, if you don’t trust these calculators, you can always calculate the bottleneck percentage of your PC system manually, although it means more work for you. You can do this by observing the CPU and GPU usage of the computer. Try using the MSI afterburner and play a game for 30 minutes. This should allow you to save a detailed log of CPU and GPU usage. (You can find the recording at C:/Program Files (x86)/MSI Afterburner/HardwareMonitoring.hml) To ensure the accuracy of the results, you will compare and try to play more games to get more information for the logs. And once the records are collected, compare them and see if there is a big difference between their usage. As mentioned above, the smaller the difference, the better.


Bottleneck calculators are a great way to get an instant idea if your PC system has a bottleneck situation. It’s also very convenient because you won’t need to physically attach a new component to test component compatibility (unlike manually observing CPU/GPU usage).

When using one online, take everything with a pinch of salt. If you’re building or upgrading a PC, don’t base your decisions solely on the information provided by the calculator. Do more research to make the right decisions, especially when upgrading hardware.

Comments are closed.