What is the CPU cache

What is the CPU cache?

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Not all CPUs are created equal, but there are some things that all have in common. One of those things is the CPU cache. So what is the CPU cache and what is it used for? What is it made of?

The CPU cache is a type of cache that the CPU uses to speed up the process of retrieving information. Instructions and other similar data that the processor has to access frequently are best stored on the cache, rather than the system memory. Both the CPU cache and the system memory are types of RAM. While the system memory is a type of dynamic RAM (DRAM), the CPU cache uses static RAM (SRAM).

The reason behind that is that SRAM is much faster. Unfortunately, SRAM can store significantly less data and it is more expensive to create, which is why we see system RAM measured in gigabytes (GB) and CPU cache in megabytes (MB). The size of the CPU cache has an impact on the CPU’s performance, so more cache generally means faster processing.

If you want to learn a more detailed answer to the question “What is the CPU cache?” and what it consists of as well as its impact on general and gaming performance, keep on reading.

Is CPU Cache Important?

There are a few things that you should consider when buying a CPU, but the CPU cache is generally overlooked. If you do not know much about computers, buying what tech reviewers suggest is not a bad idea. But if you want to be a well-informed customer, then CPU cache is almost as important as other specs, such as core and thread count, clock speed, TDP, and transistor size.

A larger CPU cache is always better, which is why one of the most powerful CPUs that you can buy today, the Ryzen Threadripper 3990X, has a combined cache size of 288 MB. You might think that 288 MB is not huge, but if you compare it to the cache size of an average modern CPU, such as the Intel Core i5-9600K that has 9 MB of cache, you will notice just how large the Threadripper’s cache is.

One of the more important reasons why new AMD Ryzen CPUs outperform Intel CPUs is the cache size, so it is an important spec. What is the CPU cache size difference here? If we compare the aforementioned Core i5-9600K with an equivalent AMD Ryzen 5 3600X, we will see that the Ryzen CPU has 32 MB of L3 cache, which is much larger than the Intel’s 9 MB.

So, you might now ask “what is CPU L3 cache” The L3 stands for level 3, which is the largest and slowest part of your CPU cache. The CPU cache generally consists of three levels: L1, L2, and L3.

What is L1 L2 and L3 Cache?

The L1 cache is also called the primary cache. It is the fastest and smallest part of the cache. It is usually found on the processor chip itself as CPU cache. The L2 cache is also called secondary cache. It is larger but slower than the L1 cache. It is also often found on the CPU chip, but it can also be a separate chip next to the dye. In case you do not know, the part that we often call processor or CPU is actually made of multiple parts that are found under the shiny metal.

And now comes the L3 cache, which is usually the one that is mentioned on the specs list of CPUs. It is the slowest and largest level of CPU cache, but it is in no way less important. L3 is usually about double as fast as system DRAM and it is physically closer to the CPU, so it has a great impact on performance. But what is the CPU cache storing?

All three cache levels are responsible for storing instructions and other data that your CPU has to access frequently. The fact that it is closer to the CPU and that it is much faster than DRAM means that it makes your CPU work faster. Your CPU will try to predict what instructions and data you are going to need. If the CPU manages to fetch the data from the cache, it is called a cache hit. If it has to get it from the system RAM, then it is called a cache miss.

The size of your CPU cache will have a direct impact on how many cache hits you are going to have. Naturally, the more hits you get, the better the performance. It also means that you will experience less stutter in games.

“But how can I upgrade my CPU cache?“, you may ask. Unfortunately, the only way to do so is to change your entire CPU. All modern CPUs have their cache located on the processor, so there is no way to upgrade it like you would upgrade your system RAM or other hardware components. But what is the CPU cache’s impact on performance in real-world usage? You will find the answer below.

How Does CPU Cache Affect Performance?

We have already mentioned that getting as many cache hits as possible will have a direct impact on your performance. It means that there is less delay between your CPU processing and fetching data and instructions.

The bigger your CPU cache, the less time your CPU has to wait before processing data. If your CPU has to fetch less data from RAM or even SSD or HDD, it means that it will work more efficiently, resulting in better performance.

Also, there is a reason why CPUs generally have a larger cache if they have more cores and threads. It allows for faster multi-threading and multitasking. That is because two different applications might need two very different sets of instructions to work. Being able to store both inside your CPU cache means less downtime.

Now, you shouldn’t buy a CPU based on the cache size alone. It probably won’t mean anything to you because you should base your purchase decision on benchmarks in programs and games that you use, not the cache size or something else.

Does CPU Cache Affect Gaming?

Now that you understand what the CPU cache is and its impact on performance, What is the CPU cache’s importance in gaming? Since the cache is used to store instructions and data that the CPU has to access frequently, and video games have such repetitious tasks, the CPU cache can have a huge impact on the performance.

A larger CPU cache will generally mean that you will get more FPS and, more importantly, less stutter. If you have ever played a competitive multiplayer game and died because of a minor stutter, you will understand why this is very important.

Nonetheless, you should not base your decision on CPU cache size alone. The core count and clock speed are going to play a far bigger role, but it is still something that you should know. If you are buying two near-identical CPUs but notice that one of them has a larger L3 cache size, then going with the bigger cache is a smart choice.

How Do I Check my CPU Cache?

If you wonder how to check your CPU cache size, there are some ways that you can do it. The easiest and fastest way is through Windows Task Manager. Simply press Ctrl+Shift+Esc and the Task Manager will pop up. Go to the Performance tab and you will see the size of all three levels of your CPU’s cache as well as some other specs.

You can also check the manufacturer’s website. All you have to do is type the CPU’s model name and go to its specifications. You will easily find the cache size.

You can also check your CPU cache size by downloading and installing a third-party program. The easiest one to use is CPU-Z. Simply download, install, and run the program. The CPU cache size will be located in the bottom right part of the “CPU” tab.

What is CPU Cache?


So, what is the CPU cache? It is a type of volatile memory that your processor uses to store and fetch data and instructions that are used commonly. A larger CPU cache will directly result in faster performance because it will take less time to fetch it from the cache than from system RAM or SSD or HDD. That is because the CPU cache is physically closer to the processor and it is made of faster SRAM, compared to the system’s DRAM.

But what is the CPU cache’s impact on performance and what does it mean for you? While having a larger CPU cache will mean that your CPU will work faster, be able to multitask better, and will achieve higher in-game FPS with less stutter, your CPU choice should not only depend on this factor alone. You should look at the overall performance of the CPU, the core and thread count, the clock speed, and other features that you are interested in before buying a CPU instead.

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