If you are a computer user, you must have heard the term Cache Memory. When you buy a new laptop, the cache memory size is mentioned in its specification. Its size is only a few MBs.
What is this cache memory? How does it affect a computer’s performance? Various such interesting information can be found in this post. By the end of this post, you will have an understanding of cache memory.
What is Cache Memory?
Cache memory is a hardware component that can store high-speed temporary data. This allows the CPU to quickly access specific data. This allows the CPU to access memory many times faster than it can access conventional memory.
Cache memory is a type of volatile memory. The computer’s central processing unit (CPU) first searches for information in cache memory. If it finds the information there, it doesn’t need to search in regular memory. This saves time and works faster.
It acts as a cache area to assist the CPU. Sometimes it is also called CPU Memory. Because this cache memory is embedded inside the CPU as a separate chip.
As it is easily accessible and close to the CPU, it can increase the performance of the processor. Its size is only up to a few MB. Because it costs more. At the same time, it can provide high efficiency.
Random Access Memory (RAM) is generally faster. But cache memory works at 10 to 100 times higher speed than RAM. Cache memory is fast enough to respond to a request from the CPU in a few nanoseconds.
We have already seen in a post about the types of RAM memory. Cache memory is of Static Random Access Memory (SRAM) type. The RAM used as the main memory is of the Dynamic Random Access Memory (DRAM) type.
Do not confuse Cache Memory and RAM Memory. Cache memory is integrated into the CPU. Its size ranges from a few MB. RAM memory is largely outside of the CPU. Its size will be in GBs.
Working Principles of Cache Memory
Cache memory is more expensive than RAM. So its amount will be very less. That is, Cache memory is available in sizes ranging from 256KB to 8MB in today’s modern computers.
When the processor tries to read a piece of data, it first looks in the cache memory. If not in cache memory, searches in main memory.
Once data is found in the main memory, it is sent to cache memory. Then it is sent from the cache memory to the processor.
Cache memory performance is measured by the Hit Ratio. The hit ratio is obtained by dividing the number of cache hits by the total number of searches. Hit Ratio = (Number of cache hits)/(Number of searches).
The purpose of Cache memory is to provide faster access to the CPU. This increases the performance of the CPU.
If a computer does not have cache memory, the CPU will send a request to RAM every time. This will take more time.
Cache memory is an intermediary between CPU and RAM.
Types of Cache Memory
There are three types of cache memory namely Level 1 (L1) Cache, Level 2 (L2) Cache, and Level 3 (L3) Cache.
Level 1 (L1) Cache
It is the first level of cache memory located closest to the processor. It is embedded individually with each core of the processor. It is small in size but very fast. Level 1 memory size ranges from 2 KB to 64 KB.Level 2 (L2) Cache
It is a secondary cache memory that can be internal or external to the processor. If the Level 2 cache is not internal to the processor, it may be shared between two cores or connected to the processor via a high-speed bus. Its speed is slightly slower than L1. The size of L2 ranges from 256 KB to 512 KB.Level 3 (L3) Cache
Level 3 cache is mounted outside the CPU. Although its speed is slower than L1 and L2, it is faster than DRAM. It is shared with all the cores in the CPU. It increases the performance of L1 and L2 cache memory. But this may be only in some high-end processors. The size of Level 3 cache memory ranges from 1MB to 8 MB.How Cache Memory Affects Performance
Although cache memory is smaller in size than RAM, it helps to increase the performance of the CPU. Cache memory is always located close to the CPU. The larger the cache size, the more data can be stored closer to the CPU.
Cache memory stores frequently used data by the CPU. Because the access speed of cache memory is high, the CPU retrieves data quickly.
Every time the CPU accesses the main memory, to retrieve data, time is wasted. Because the CPU has to wait until the data is retrieved. But Cache memory reduces that waiting time.
The higher the cache size, the faster the CPU. This can make computer programs run faster.
How to Check Cache Memory in My Computer
You can check the amount of cache memory in the CPU of the computer you are using. Here are the procedures for that: First press the Control + Shift + Esc buttons on your computer keyboard. Now Task Manager window will open. In the Task Manager click on the second tab Performance and then select CPU.
Should You Consider Cache Memory When Buying a Computer?
There are various specifications that you will consider when you buy a computer. Your buying decision will not only depend on cache memory.
Most of the computers coming out now have a cache memory of 2MB or 4MB or 8MB by default. So consider Clock speed, Number of cores, and Number of threads to increase CPU performance. Check out the Laptop Buying Guide article to know how to choose a laptop.
This article will help you understand what cache memory is and how it works. If you want to upgrade your computer’s CPU, the cache memory can be a factor when looking for the right CPU.