Computer components have different tiers. It’s possible to get one component that is significantly faster than another. In this article, I will explain if a good GPU can run with a bad CPU.
A good GPU can run with a bad CPU. But, it is not ideal. Ideally, the CPU should match the GPU, with the GPU being slightly faster. A bad or slow CPU will not be able to fully utilize a GPU that is significantly better. The GPU will likely max out at 50% utilization, where 100% utilization is the best.
Having a good GPU is better than having a slow GPU or an integrated GPU. But, below I will cover:
- If a good GPU makes up for a bad CPU
- If CPUs limit the GPU
- If you need a good CPU when you have a good GPU
Let’s dive in!
Does a Good GPU Make Up For a Bad CPU?
A good GPU provides better performance for gaming, and resource intensive tasks such as rendering video. The speed of the CPU is a key factor that limits how fast a computer is.
In general, a GPU that is significantly better than the CPU is not worth it. A good GPU does not make up for a bad CPU. Independent tests have shown that a computer with a GPU that is significantly better than the CPU does not offer a performance boost.
It’s ideal for the CPU to match the GPU. With the GPU being slightly faster. Here’s a table that shows different configurations for the CPU and GPU, and which is the best:
| CPU and graphics card (GPU) specs | Performance |
| Fast CPU, slow GPU | Bad |
| Slow CPU, fast GPU | Bad |
| Close to evenly matched CPU and graphics card | Best |
The reason why is that either the CPU or the GPU needs to wait for the other component, as shown in the table below:
| CPU and GPU speeds | Why it’s worse | Way to improve performance |
| CPU is too fast for the GPU | CPU is waiting on the GPU | Get a better GPU |
| GPU is too fast for the CPU | GPU is waiting on the CPU | Get a better CPU |
| GPU is equal or slightly faster than the CPU | – | None. |
It’s true that getting a better GPU provides the most significant performance improvement. But, it’s only to a point. Beyond that the CPU can not send instructions to the GPU to utilize it completely. For that reason the extra power a much faster GPU has is in practice wasted.
On the other hand, when you get a better CPU. You can keep your existing GPU, and see a very significant improvement in performance.
READ MORE >> Is 99% GPU utilization good
How to know if a GPU is too fast for your CPU
There are no clear guidelines about how to know if a GPU is too fast for a CPU. The best way is to look at custom PC builds on websites like LogicalIcrenements.com. They provide a list of about 15 different custom builds based on budget.
These include the graphics card, and CPU. You can get an idea of what CPU matches what graphics card by looking at those. And then finding a similar priced CPU or GPU. Or, getting the best in category by using information on websites like CPUbenchmarks.com.
Provided they are similarly priced, or the exact same as the recommended custom builds you can be sure they match. If you have a bit more budget then get a slightly better GPU. But, not one that is a few tiers above.
Another significant factor is RAM.
READ MORE >> What’s more important CPU cores or RAM
It covers if RAM speed affects computer performance. And how to know what speed and how much RAM is ideal based on what you’re using your PC for.
Do CPUs Limit the GPU?
CPUs do limit the GPU. If the CPU on a computer is slower than the GPU the GPU won’t be fully utilized. On all pre-built computers the CPU and GPU are perfectly matched. But, on a custom built computer, it’s important to get a CPU and GPU that match. Doing so provides the best performance.
There are two potential scenarios:
- The CPU is too slow for the GPU – the GPU isn’t fully utilized
- The GPU is too slow for the CPU – The CPU isn’t fully utilized
A GPU has a capacity that fluctuates from 0% to 100%. You can see what it is by opening the Windows Task Manager, and clicking on the performance tab on the left hand side.
It’s common for the GPU utilization percentage to be 0% when you are just browsing the web. However, when gaming, the GPU utilization commonly goes up to 100% and stays at 100%.
When this happens it’s ideal. But, if the CPU is too slow for the GPU, the GPU utilization percentage will be lower. Anything under about 70% when playing a game on the highest graphics settings indicates that the CPU is too slow for the GPU.
Do You Need a Good CPU if You Have a Good GPU?
You do need a good CPU if you have a good GPU. It’s possible to use a good GPU with a bad CPU. But, your GPU will not be fully utilized. The ideal combination is a good CPU and a good GPU. To know if a CPU will match a GPU refer to this section of this article.
Overall, it’s not ideal to get a GPU that is significantly better than the CPU. The extra performance the GPU has can’t be utilized by the CPU. A GPU that is slightly better than the CPU, is best.
For an existing computer, the way to know if your CPU is too slow for your GPU or the other way around is to open the Windows Task Manager. Take a look at the CPU usage percentage, and the CPU usage percentage when doing something resource intensive. Such as, playing a graphics intensive game.
Here’s a table that shows how to interpret the CPU and GPU usage percentages:
| CPU usage percentage | GPU usage percentage | What it means |
| 100% | 100% | GPU and CPU perfectly match |
| 100% | 50% | CPU is too slow for the GPU |
| 50% | 100% | GPU is too slow for the CPU |
| 50% | 50% | CPU and GPU perfectly match and are very high end. Or, you can turn the graphics settings up |