The term “bottlenecking” is spoken a lot in the PC building community, especially among gamers that want the most FPS possible.
Usually when someone experiences FPS issues, one of the many reasons for that can be a bottleneck, this is why it’s discussed a lot.
FPS drops can be caused by a bottleneck, but it depends on what component is causing the bottleneck. Usually, FPS drops are caused by RAM bottlenecks.
What Is A Bottleneck?
A bottleneck defines a component that restricts or limits the performance of another component, it’s usually caused by pairing a weaker component with a significantly stronger component.
The most common form of a bottleneck is when the CPU bottlenecks the GPU. This usually happens when you pair a really strong GPU with a mediocre CPU.
But it’s important to realise that bottlenecks aren’t exclusive to CPUs, and GPUs, many other components such as the RAM can cause bottlenecks.
This is why it’s stressed that you build a balanced system especially when building a gaming PC, this reduces the effects of bottlenecks.
How Does The CPU Affect FPS?
The CPU and the GPU have a close relationship with each other, the job of the CPU is to process and keep up with the data coming from the GPU.
A faster CPU can keep up with the immense processing that the GPU does, but what does it mean to have a fast CPU especially in gaming terms?
Well, when we think about building a gaming PC for maximum FPS, we don’t usually think about picking the CPU with the most cores.
We usually think about picking up the CPU with the most single-core performance, so, clock speed, and IPC make the biggest difference in terms of gaming.
More Cores Or Higher Clock Speed For Gaming/FPS
To put it simply, games benefit significantly more from clock speed rather than cores because games are coded in such a way that single-core performance has more of an impact.
But that simply isn’t the case, most gaming PCs use I5s and Ryzen 5 CPUs that have around 10 cores, so clearly clock speeds is the more important metric.
Often, Ryzen 5s and I5s will have clock speeds that are similar to their more powerful counterparts (Ryzen 9 & I9) which means the difference in FPS won’t be as dramatic.
Also Read: Clock Speed Vs Cores For Gaming
Does CPU Cache Bottleneck Cause FPS Drops
Besides single-core performance, the CPU cache is probably the second most important metric for FPS and gaming performance.
This is because the CPU cache has a direct impact on how fast the CPU can find and process information.
When gaming, the CPU cache can pretty much run out of space depending on the CPU, this is what we call a CPU cache bottleneck.
When the CPU cache runs out of space, the CPU will have to go to the main system memory which is the RAM, and the RAM is significantly slower than the CPU cache.
Because the CPU cache works at a significantly higher clock speed, typically close to the CPU cores clock speed, switching to the main system memory can cause a major hindrance in performance.
So yes, a CPU cache bottleneck can cause FPS drops, and this FPS drop usually occurs when the CPU cache runs out of space.
Also Read: Does CPU Cache Affect Gaming
RAM Can Bottleneck And Cause FPS Drops
Yes, the RAM can bottleneck and cause FPS drops, this is due to the RAM and the CPU sharing data/instructions with each other.
This is why it’s important for gamers to pick their RAM carefully, there’s a few RAM specifications you should watch out for such as RAM speed and capacity.
Also, the RAM matters especially more if you’re running a Ryzen based system, this is because Ryzen processors are more sensitive to RAM speeds.
Slow RAM Can Affect FPS
Slow RAM can affect FPS, this is because the slower the RAM is, the slower it will send and receive information.
This often means the CPU will have to wait longer on instructions, and when the CPU is waiting, this can cause the GPU to also slow down.
As you can see from the screenshot above, the slower RAM module(2133MHz) falls significantly behind the 2666MHz RAM stick.
But then the jump between 2666MHz to 3200MHz is much smaller, so it seems that the RAM speed can cause FPS drops if it’s too slow.
But increasing the RAM speed past a certain point will definitely result in diminishing returns, so it’s best to find a sweet spot which is 3200MHz.
Also Read: How Much Does RAM Speed Affect FPS
RAM Capacity Can Affect FPS
It’s generally stated that most gamers should go for 16GB of RAM, anything less will cause issues, and anything more won’t really give more FPS.
And there’s good reason for this, the majority of games will not use more than 16GB of RAM, so there’s really no point going for more RAM.
As you can see from the screenshot above, the PC build with 8GB of RAM has significantly less FPS than the 16GB build.
After that, the difference in FPS between the 16GB, 32GB, and 64GB build is non-existent, this shows that games will mostly use 16GB of RAM.
The reason why having less than 16GB of RAM can cause a significant FPS drop is because once the RAM runs out of capacity, the CPU will have to go to the permanent storage (SSD or HDD) for instructions.
And the SSD and HDD is significantly slower than RAM, so as well as receiving FPS drops, you may also be prone to freezing and crashes.
CPU, Resolution & FPS – What’s The Relationship?
There’s a relationship between the CPU, Resolution, and the FPS, and it’s quite interesting. The lower the resolution is, the higher the FPS is, but the CPU usage will also increase.
With higher CPU usage, this implies that the CPU is finding it difficult to keep up with the graphics card, this implies a potential bottleneck.
So yes, lower resolutions can and will cause bottlenecks, this is because the more frames the GPU is pushing out, the more work the CPU has to do.
This is the reason why the CPU will bottleneck at 1080P, so you may experience slight FPS drops if you’re gaming at low resolutions.
Also Read: Why Does CPU Bottleneck At 1080P
How Can I Reduce Bottlenecks?
Yes, reducing bottlenecks is possible, but you need to identify what is actually causing the bottleneck first.
Fixing a CPU bottleneck can be easy, usually overclocking, and increasing the in game resolution should solve the issue, but this isn’t always possible.
So, the best way to fix the CPU bottleneck would be to buy a new processor with better single-core performance.
If your RAM is the cause of the bottleneck, then it’s extremely likely that you’ll need to purchase more RAM or faster RAM.
Conclusion – So Does Bottlenecks Cause FPS Drops?
Yes, a bottleneck can definitely cause FPS drops, and it can be caused by many factors such as insufficient RAM capacity, slow RAM, and insufficient CPU cache.
So if you notice a significant FPS drop in game, you can use an FPS overlay software which will display what is exactly bottlenecking your hardware.
If it shows that your CPU is running at 100%, then it means your CPU is the bottleneck, in this case, you need a stronger processor.