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How to tell if CPU is bottlenecking GPU

by Linda D. Yelverton

Even if you have the best GPU installed, if your CPU is not upgraded, you might be missing out on lots of things. Have you ever wondered whether your CPU is bogging down the performance of your GPU? Are there any ways to find out if your CPU is bottlenecking your GPU? Yes, there are and we are going to talk about ways to find that out.

The bottleneck is one problem that bothers several PC gamers. While there are various hardware issues associated with this condition CPU bottlenecking the GPU is very much likely. This guide will tell you why this bottleneck is prone to occur. You will also learn how to know whether the problem is really originating from your CPU. In the end you will know how to tell if CPU is bottlenecking GPU.

Here are a few things you need before tackling your bottleneck problem-

  • You should understand what a bottleneck is
  • You should identify the signs that indicate that your CPU is causing the bottleneck
  • You should know how to address the issue

Understanding what a bottleneck is

There are times when even the best processor reaches its processing limits. This means that if you throw any further action at the processor it would not be able to efficiently handle it. When this happens to your CPU it can in turn impact the performance of your GPU which is hardware associated with the processing unit.

The above hurdle happens especially when you are playing games on the computer. Unlike the normal tasks of computation, gaming requires multiple functions to be carried out in the CPU. Most of these might also happen simultaneously. There is AI processing, game sound and game logic handling, and UI responsibilities. All these are then topped up by the game rendering. There are draw calls issued so as to enable the CPU and GPU collaboration which is essential for the rendering of the graphics. Therefore when the CPU gets sluggish it takes a toll on the performance of the GPU. This means that your GPU is not functioning at its best condition. This is where a bottleneck occurs.

How can you tell that the GPU is struggling because of a CPU bottleneck?

The tricky part about understanding the relationship here is that this is a dynamic issue. The state might be different for different games. Therefore it might seem difficult to interpret at first glance. You should understand whether your game and the game settings are truly GPU bound or CPU bound. The following are the ways in which you can monitor the performance of your computer in general and also identify whether the CPU is the cause of the bottleneck.

  1. The most straightforward method to find out if your CPU is bottlenecking your GPU is by taking a peek into your Task Manager (in the case of a windows machine). You would be able to view the CPU status in the Performance tab. Besides learning about the utilization of the CPU you would also get to know the number of cores being used. This is also where you get to see the GPU utilization. The higher the value of the GPU utilization rate, the brighter are the chances that your CPU is bottlenecking the graphics card. If the value is close to 100 then your CPU has already reached its full potential. You would also be able to view the proportion of GPU memory being utilized which further strengthens your observation about the fault being on the CPU.
  2. There are apps that help understand CPU performance during games. These apps when installing overlay the details like frame rate, GPU and CPU utilization and more. While you play your games you would be able to view these details displayed real time. If the frame rate of the game happens to be way over 60fps then the GPU handles it most of the time. The situation can be handled better with multiple graphics cards. If the game comes with an optimized graphics performance then it would make the most of both the cards. Therefore your CPU would not handle the strain single handed and the bottleneck therefore doesn’t arise from the CPU. If the frame rate happens to be below 60fps and the graphic cards are not being used to their fullest these are CPU bound games. For such games, when the CPU utilization percentage increases bottleneck happens.

How can you tackle a bottleneck?

CPU is bottlenecking GPU

Knowing how to address bottleneck issues can help improve your gaming experience. Here are some of the tricks that work-

Close background processes

While playing your game for optimized performance or your computer killing the background processes is a trick that nearly every gamer would vouch by. While the game processes themselves add plenty of load on your CPU you definitely do not want unwanted background processes to make things worse.

Optimize the game

We are talking about tweaking the resolution of the game. Alter the resolution settings so that the weight is distributed to the GPU rather than the CPU. Rendering times increase for higher resolutions and this extended time allows the CPU to get back on track.

RAM or CPU clocking

Overclocking of the CPU itself or just the RAM can add some speed to your computer. This allows quicker data processing and more powerful performance.

Wrapping it up

CPU bottlenecking the GPU is not uncommon. Therefore there is no need to panic when this does occur. Before you jump to make any decisions about making hardware upgrades try simpler ways. The above-mentioned methods can be seen as quick fixes for such sluggish machines. You can easily add some CPU headroom by following the above steps. Hope you also understood how to look for signs that depict the role played by the CPU in a bottleneck faced. Try out these simple tricks and let us know if you notice any changes in your favorite games. This can make your old computer function as smooth as a new machine in no time.

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