How to Know Which Component is Bottlenecking Your Gaming PC

By | February 6, 2016

Intro

One of the most frustrating experiences when upgrading a gaming computer is figuring out what parts actually need upgrading. While you can post on message boards and seek out advice, many times those giving the advice are misinformed, which can lead to users wasting money on upgrades that offer them little to no benefit.

The most important fact to understand is that different games tax hardware differently. Some games may require a top of the line graphics card to run at an acceptable frame rate, whereas some games, especially online ones and those with complex physics, require a high end CPU to run well. You may find that some of your games run slowly due to your graphics card, whereas others are limited by your CPU.

 

Common Misconceptions

  1. “My CPU usage isn’t at 100%, therefore my CPU isn’t the bottleneck!”

Many games are limited by something called single-threaded performance. Modern processors are split into multiple cores. Each core will perform its own task at the same time as the other cores. The problem is, many tasks rely on other tasks to be finished first, so not everything can be done in parallel(at the same time).

Consider this analogy. When making a cake, you must first bake it before you decorate it. Even with 2 people, you cannot bake a cake and decorate it at the same time.

When running a game, you might have 4 cores, but maybe only 2 are working, because they’re working on something that cannot be done in parallel. As a result, the game may show as only using 50% of your CPU in the task manager. What’s actually happening is that the individual cores cannot work fast enough on their own, and the code isn’t designed to utilize all the cores of your processor at the same time.

2. “I have [name of high end product], it can’t be bottlenecking me!”

Sometimes, games or applications might be poorly coded, or the features they contain may be too demanding for what current consumer hardware allows for. It could be that your high end product is bottlenecking you, and if that is the case, it simply means that there’s nothing you can do about it except wait for better hardware to come out, or complain to the developer and hope they fix it.

Finding the Bottleneck

To find the bottleneck, you need to measure the load of each device while running your games.

To measure the graphics card load, I recommend MSI Afterburner. MSI Afterburner is a free application the enables you to view data regarding your graphics hardware, as well as provide functionality for overclocking and custom fan control.

After installing MSI Afterburner, load up one of the games you feel aren’t performing up to your expectations. Be sure to turn off Vsync or any settings that might be setting a cap on your frame rate. I also recommend setting your game to run in Borderless if the game settings allow it, in order to make it easier to view the information while playing the game. If you must use windowed, be sure to set the resolution as close as you can to the resolution you play at in full screen by resizing the game to cover the majority of the screen. GPU load increases significantly at higher resolutions, so it’s important to mimic your usual setup as closely as possible.

First, pay attention to the “GPU1 Memory Usage”. If the memory usage is more than 90% of what your graphics card contains, it’s possible you may be bottlenecked due to lack of graphics memory. You can address this by reducing texture settings in game to reduce VRAM usage at the cost of image quality, or by purchasing a newer graphics card with more VRAM. Just make sure the graphics card you buy is actually more powerful than what you have now, as video memory is only one of many components that matter in a graphics card.

Next, look at “GPU1 Usage” and “GPU1 Core Clock”. If GPU usage is lower than 90% or the core clock is running at lower than the advertised speed of the graphics card, then it’s likely your processor(CPU) is bottlenecking you.

Lastly, open the task manager by pressing control+shift+escape. If on windows 8 or 10, click more details. If your Memory usage is greater than 95%, it could be that you do not have enough RAM installed. You can address this by either closing extra applications you have open while gaming, or installing additionally memory. Just make sure you purchase the correct type.

Additional Notes

Moving your games to a solid state drive instead of a traditional hard drive can significantly improve load times. In addition, for open world games such as Grand Theft Auto and Black Desert, it can also fix issues with objects not appearing quick enough when traveling at high speeds, by ensuring that graphic files can be read from the storage device quickly. In some cases, it may even solve issues with stuttering.

Conclusion

Through using MSI Afterburner and the task manager, you can determine which device is the limiting factor for each game you play. When upgrading your device, be sure to research the devices you will purchase to determine how much faster it is than your current device. Anandtech has real word benchmarks for graphics cards, and plenty of sites exist for CPU benchmarks.

One thought on “How to Know Which Component is Bottlenecking Your Gaming PC

  1. Randomguy

    Cool post.
    Remember Rivatuner has also a built-in OSD you can use in-game, with no need of windowing the game.

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