What is Cache in the CPU? [2023]

A CPU memory cache is a rapid form of memory inside the processor. In the history of computers, memory and processor speeds were slow. However, CPU speeds started to multiply. CPU cache memory was created due to the system memory at the time (RAM) unable to keep up with or equal the growing CPU speeds. Your computer now has a variety of memory types. The operating system and programs are primarily stored in central storage, a hard drive, or SSD.

The CPU memory cache inside the CPU has even quicker memory units. Computer memory is arranged in a hierarchy based on how quickly it operates. The quickest component in this hierarchy is the CPU cache. As a CPU component, it is the closest to where the primary processing takes place. While your primary system RAM is called Dynamic RAM, cache memory is a type of Static RAM (SRAM) (DRAM), making SRAM an excellent choice for cache memory.

Key Takeaways

Cache is a small and fast memory that stores frequently used data and instructions for the CPU.
Cache reduces the latency and bandwidth of accessing the main memory, and improves the performance and efficiency of the CPU.
Cache is divided into levels (L1, L2, L3, etc.), each with different size, speed, and proximity to the CPU core.
The higher the level of cache, the larger and slower it is, but it also covers more data and cores.
Cache is one of the important factors that affect the CPU performance, along with clock speed, core count, and architecture.

Table of Contents

How does cache memory work?
Cache Memory Levels: L1, L2, and L3
L1 Cache Memory
L2 Cache Memory
L3 Cache Memory
Conclusion

How does cache memory work?

We have already explained what is cache in the CPU. Now, it’s time to understand its operation. Your computer’s programs and applications are created as a collection of instructions that the CPU interprets and executes. Data is initially loaded into RAM before being delivered to the CPU. Modern CPUs are capable of processing an enormous amount of instructions per second. The CPU cache allows the CPU to access concise memory, allowing it to utilize all of its power.

The CPU then transfers data back and forth via the memory cache. Additionally, there is a hierarchy of memory in the CPU cache. The most recent CPUs will logically have more CPU cache memory than earlier generations and may also have quicker cache memory. Learning how to compare CPUs efficiently is one thing you can do. There is a tonne of information available, so understanding how to contrast and evaluate several CPUs might assist you in making the best choice.

Cache Memory Levels: L1, L2, and L3

There are three types of CPU cache memory: L1, L2, and L3. Again, the size of the cache and speed determine the memory structure.

	L1 Cache Memory:	L2 Cache Memory:	L3 Cache Memory:
Size (approximately)	32 KBytes	256 KBytes	6 MBytes
Descriptor	Eight-way Set associative	Eight-way Set associative	12-way Set associative
Latency	4 cycle	12 cycle	~21 cycle

L1 Cache Memory

The fastest memory available in a computer system is called the L1 (Level 1) cache. The data that the CPU will most likely require while performing a particular job is stored in the L1 cache and accessed with the highest priority.

L2 Cache Memory

Although L1 caches may be measured in kilobytes, modern L2 memory caches are gigabytes in capacity. Although L2 (Level 2) cache is slower than the L1 cache, it is more powerful. The standard L2 cache size in modern CPUs is 256 KB or more, and this site is now viewed as little. Memory caches more significant than 8MB are found in some of today’s most powerful CPUs.

L3 Cache Memory

The L3 (Level 3) cache is now active. The L3 memory cache used to be located on the motherboard back in the day. This was back when single-core CPUs were the norm, a very long time ago. The L3 cache in your CPU may now be enormous; the leading consumer CPUs have L3 stores of up to 32 MB.

Some server CPU L3 caches can offer up to 64 MB, exceeding this limit. Although it is the biggest, the L3 cache is the slowest memory. The L3 store is a component of modern CPUs.

Conclusion

CPU cache memory comes built-in into the CPU and increases processing, and helps improve a computer’s performance. However, CPU speeds started to multiply. CPU cache memory was created due to the system memory at the time (RAM) being unable to keep up with or equal the growing CPU speeds. Your computer now has a variety of memory types. The operating system and programs are stored primarily in the primary storage, a hard drive or SSD.

Modern CPUs are capable of processing an enormous amount of instructions per second. Although L1 caches may be measured in kilobytes, modern L2 memory caches are gigabytes in capacity. Although L2 (Level 2) cache is slower than the L1 cache, it is more powerful. L3 Cache Memory: The L3 (Level 3) cache is active. There is a tonne of information available, so understanding how to contrast and evaluate several CPUs might assist you in making the best choice.

Arslan Ashraf

CPUs & CPU Cooler Expert

Arslan Ashraf is a dedicated tech writer with a rich background in Computer Science and five years of experience in the field. While pursuing his Bachelor's degree from Virtual University, he has honed his expertise in CPUs and CPU Coolers. His ability to simplify complex technological concepts has made him a valuable resource for a wide audience. Driven by passion, Arslan remains at the forefront of industry trends, delivering expert insights that continue to enlighten his readers.