What is the Difference Between L1 L2 and L3 Cache? with Proper Definition and Brief Explanation

The main difference between them is that L1 cache is the fastest cache and L3 cache is the slowest cache while L2 cache is slower than L1 cache but faster. than the L3 cache.

Cache is a fast memory in the computer. Contains data frequently used by the CPU. RAM or primary memory is fast, but cache memory is faster than RAM. The CPU first checks the cache to find the required data. It works as the intermediate layer between the CPU and RAM to provide data faster to the CPU. Thus, it helps to increase the calculation speed of the device. There are three types of cache like L1, L2 and L3.

Key Areas Covered

1. What is the L1 cache?
      – Definition, Functionality
2. What is the L2 cache?
     – Definition, Functionality
3. What is the L3 cache?
     – Definition, Functionality
4. What is the difference between L1 L2 and L3 cache
     – Key differences comparison

Key terms

Cache memory, L1 cache, L2 cache, L3 cache

What is the L1 cache?

L1 cache is the level 1 cache. We also call it the main cache . It works at the same speed as the CPU. Also, it is the fastest cache among all other caches. Also, it is smaller than other caches, which are L2 and L3. Also, each core in the CPU has its own L1 cache.

What is the L2 cache?

L2 cache is the level 2 cache. It stores data that is not stored in the L1 cache. In other words, if the CPU can’t find the data it’s looking for in the L1 cache, it checks the L2 cache. Also, the L2 cache is larger than the L1 cache but smaller than the L3 cache. Each code in the CPU has its own L2 cache.

What is the L3 cache?

L3 cache is the level 3 cache. It stores data that is not cached in L1 and L2. In other words, if the CPU can’t find the data it’s looking for in the L1 and L2 cache, it checks the L3 cache. Also, the L3 cache is the largest among all caches. Also, all cores in the CPU share the same L3 cache.

First, the CPU checks the L1 cache for data. If it is not available, it will check the L2 cache. If the data is not available, it will check the L3 cache, and if the data is not available in L3, it will check the RAM.

Key Differences

Definition

The L1 cache is a cache memory that is directly integrated into the processor and is used to store information that was recently accessed by the CPU. In contrast, the L2 cache is cache memory that is outside and separate from the core of the CPU chip, even though it is on the same chip package as the CPU. Meanwhile, the L3 cache is a cache that is used by the CPU and is usually built into the motherboard within the CPU module itself. Therefore, these definitions contain the basic difference between them.

Size

Size is also an important difference between them. The L1 cache is the smallest, while the L3 cache is the largest. The L2 cache is larger than the L1 cache but smaller than the L3 cache.

Synonyms

L1 cache is called level 1 or primary or internal cache, while L2 cache is called level 2, secondary or external cache and L3 cache is called level 3 or external cache.

Velocity

Speed ​​is another significant difference between them. The L1 cache is the fastest and the L3 cache is the slowest, while the L2 cache is slower than L1 but faster than L3 cache.

Association with CPU Cores

Each CPU core has its own L1 cache, while each CPU code has its own L2 cache. However, all cores in the CPU share the same L3 cache. Hence, this is another difference between them.

Conclusion

Cache memory is a computer component that stores data so that future requests for data can be served faster. There are three types of cache like L1, L2 and L3. The difference between them is that L1 cache is the fastest and L3 cache is the slowest while L2 cache is slower than L1 but faster than L3 cache.

Reference:

1.  CPU Cache Explained – What is cache? , PowerCert Animated Videos, Nov 27, 2016, Available here.

Courtesy image:

1. “ذاكرة الكاش” By Ammar soud91 – Own work (CC BY-SA 3.0) via Commons Wikimedia

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