CPU and GPU Bottleneck: A Detailed Explanation

1. visual representation of CPU bottlenecks

Have you ever experienced playing a game and you get sudden FPS drop from time to time? The next second, you’re dead..

If you try to observe, these sudden FPS drops show up when you kill an entire army of mobs all at once. Perhaps the screen shows damages inflicted to at least 1,000 mobs with your massive fire AOE skill. Anything that shows a huge amount of text or a huge change in graphics usually drops the FPS.

Why is this happening..?

We all just want a smooth gaming experience.

That, my friend, is a matter of CPU bottleneck or GPU bottleneck. Jump in as we talk about CPU and GPU bottleneck in detail, as well as ways to address bottleneck issues.

Defining Bottleneck, CPU Bottleneck and GPU Bottleneck

Bottleneck, as for how it is named, occurs when there is a limit on how much data is being sent for processing or how much data can be processed at the same time. In other words, this means that the capacity to return a processed data is not enough compared to how much data is being sent for processing.

The components that are involved in the process of bottlenecking are the CPU (processor) and the GPU (graphics card).

If they have huge differences in processing speed, bottleneck will happen. We’ll talk more about the details of the processes later.

CPU Bottleneck

CPU bottleneck happens when the processor isn’t fast enough to process and transfer data.

A good example of which is to look at an AMD A6 5th gen processor paired with a GTX 1080 Ti  graphics card.

On paper, a GTX 1080 Ti can easily run games with improved graphics details. However, because the A6 processor can’t keep up with the processing speed of the graphics card, CPU bottleneck happens.

The CPU is what’s responsible for processing real-time game actions, physics, UI, audio and other complex CPU-bound processes. A bottleneck happens if the speed of data transfer is capped. See the image below for a better visual representation of what’s happening when a CPU bottlenecks.

1. visual representation of CPU bottlenecks

A solution to balance out the processing speeds can be made by adjusting resolutions - we’ll have this covered later in detail.

GPU Bottleneck

The same concept applies to GPU bottleneck - only this happens if you pair a fast processor with an entry level graphics card.

Let’s take an Intel Core i7-8700K processor and pair it with a GT 1030 graphics card.

Without a doubt, the Core i7 processor can process games fast. It processes so fast that the GT 1030 just doesn’t have the speed to return the processed data back.

Causes of CPU and GPU Bottleneck

Now let’s talk about what really causes a CPU and a GPU to bottleneck.

With what we have discussed so far..

You may think that it’s either you just have a slow processor or a poor graphics card that causes it.

No. Games themselves also are contributing factors why we get CPU or GPU bottleneck.

Games are not designed to be similar. Although they change in line with the set in-game settings, there games that are CPU dependent and GPU dependent.

CPU dependent games are those that usually have high FPS rate with low-resolution graphics. Among these games include:

  • Cities: Skylines
  • Minecraft
  • Civilization V
  • Assassin's Creed: Black Flag

Games that show higher frame rates when paired with a high-end graphics card are GPU dependent games. Here are some games that are notoriously dependent on GPU.

  • The Witcher 3
  • Metro: Last Light
  • Borderlands 2
  • Dying Light

Overall, causes of CPU and GPU bottleneck are not solely limited to the components themselves.

This is why you need to choose a specific gaming setup carefully by basing it in line with what games you usually play. Starting with this keeps you from having a need to “upgrade” your components anytime soon.

Ways to Address CPU and GPU Bottleneck

There isn’t a way to see whether your CPU or GPU is the culprit of what’s causing the bottleneck. You can do this by downloading a monitoring software like MSI Afterburner.

We have included a download link here for your convenience. Just go to the downloads tab and click on Download Afterburner button from there.

Monitoring Your CPU and GPU Processes

With the MSI Afterburner opened and set, log both your CPU and GPU usage when gaming or you can simply open the monitoring window when gaming. This allows you to see every load on your CPU and GPU.

If your CPU reflects high usage with low GPU usage, you have a CPU bottleneck. Similarly, this means that the game is CPU dependent.

Looking at the flip side, if your GPU loads are spiking while your CPU loads are at low levels, you have a GPU bottleneck. This also means that the game is dependent on GPU.

Fixing Your Bottleneck Issues

Addressing or fixing the bottleneck issues you have with your CPU or GPU is easy. The key is to balance out the processing load of both components to play a similar rhythm.

Method 1: Increase the game’s resolution

If you have a CPU bottleneck, increasing the processing usage of your GPU should “balance” the load. By adjusting your game’s graphics to higher (4K) resolutions, the GPU will need more time to render the processed data.

Have your CPU and GPU process data at a common speed to see fewer chances of experiencing bottleneck.

Method 2: Stop unnecessary background process

A great way to lower your CPU bottleneck issues is to close your background processes. Doing so leads to a surprising increase in FPS count.

2. close your background processes

Method 3: Overclock the RAM

RAM is closely tied to how fast the CPU can process data. By overclocking the RAM, a huge boost in performance and FPS can be seen.

3. a huge boost in performance and FPS can be seen

Method 4: Overclock the CPU

Overclocking the CPU (or a locked CPU) offers more room for the processor to breath.

4. Overclocking the CPU

Method 5: Lower CPU-intensive game settings

Lowering in-game CPU-bound settings allow a huge boost and reduction in CPU bottleneck issues. These settings include but are not limited to lowering draw distance, vegetation, population density, and others.

5. Lowering in-game CPU-bound setting

Video:

Unfortunately, there are not much solutions gamers can do on fixing a GPU bottleneck besides adjusting the graphics to lower settings. On the bright side, getting GPU bottleneck is better since this does not return stutters in the game unlike getting a CPU bottleneck.

Conclusion

CPU bottleneck and GPU bottleneck are both different issues of the same platform. A wrong pair of processor and graphics card usually is what causes a bottleneck.

This is why gamers need to pair the right components before actually getting the parts. Choose components in line with the games you usually play to avoid the need to upgrade soon.

By pairing the right components, chances of experiencing bottleneck will be slim.

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