Cache memory plays a crucial role in computers. Advanced computer systems, including desktop PCs, servers in enterprise data centers, and cloud-based computing resources, have a small amount of high-speed static random access memory (SRAM) that is very close to the central processing unit (CPU).
This memory is cache memory. Even though its small size compared to primary memory (RAM) or secondary memory (storage resources), cache memory dramatically affects the system’s overall performance.
What is cache memory?
Computer systems consist of hard disk drives or solid-state drives (SSDs) to provide high-capacity, long-term data storage, and RAM, which is used to store data and program code using a central processing unit.
Has been or is needed. RAM is faster than hard disk drive or SSD storage. It is usually made up of Dynamic Random Access Memory (DRAM), which is more expensive per gigabyte of stored data.
But a CPU works faster than RAM, so it may sometimes be forced to wait until manual or data are read from RAM before it can continue processing. The overall performance of the computer system decreases.
Cache memory, a tiny amount of dynamic random access memory, is often found in modern computer systems (DRAM), which is highly quick but also very pricey and is situated near the CPU.
Data or instructions that the CPU will likely utilize in the future are stored in this cache memory. Caching is used to speed up reading since it stops the CPU from having to wait for the data to be read.
Cache memory and performance
Cache memory enhances computer performance. Cache memory is situated very close to the CPU. Either on the CPU chip itself or the motherboard near the CPU and connected via a dedicated data bus. So it can read (and write) instructions and data much faster than standard RAM.
It means CPU waiting is less likely to be delayed – or you will dramatically reduce waiting times. The result is that a minimal amount of cache memory can significantly increase computer performance.
How does cache memory work?
Cache memory works in RAM by taking data or instructions to a specific memory address and copying these instructions or data to the cache memory with the original address record.
It results in a table containing a small number of RAM addresses and copies of instructions or data with these RAM addresses.
Memory cache “Hit.”
When the processor needs instructions or data from a given RAM address, it checks the cache memory to see if there is any reference to that RAM address before retrieving it from RAM.
If this happens, it reads data or instructions related to cache memory instead of RAM.
It is known as a “cache hit.” Because cache memory is faster than RAM and is located close to the CPU, it can retrieve instructions and data very quickly and start processing it.
The same procedure is performed when you must write data or instructions back to memory. Because if anything is written to cache the memory, it should eventually be written as RAM.
The most specific policy is known as “right throw”: with this policy, anything written on the memory cache is immediately reported to RAM.
An alternative policy is “right back.” Using the “write back” policy, data written to the cache memory is now instantly written to RAM.
Anything written on cache memory is marked as “dirty,” meaning it differs from the actual data or instructions read from RAM. When it is removed from cache memory, it is written to RAM instead of the original information.
Intermediate policies allow “dirty” information to be lined up and written back to RAM, which can be more beneficial than multiple individual entries.
Memory cache “Miss.”
If the data or instructions at the given RAM address are not found in the cache memory, it is called “cache miss.” In this case, the CPU must wait until the data is recovered from RAM.
Data or instructions are retrieved from RAM, written to cache memory, and then sent to the CPU. It is because recently used data or instructions are more likely to be needed again shortly. So, whatever CPU requests from RAM is always copied to the cache memory.
(There is an exception. Some data is of the type that is rarely reused. You can mark it as non-cacheable. This valuable cache memory space is unnecessary data. Prevents the capture of
The answer is that some of the cache memory content has to be “erased” to make room for new information that needs to be written there.
If a decision needs to be made, MemoryCash will apply a “change policy” to determine which information has been removed.
There are several possible alternative policies. One of the most common is the recently used (LRU) policy. This policy uses the principle that if data or instructions have not been used recently, they will be less needed shortly than the data or instructions that You recently required.
The critical value of cache memory
Cache memory is required to reduce performance barriers between RAM and CPU. Using it is equivalent to using RAM as a disk cache.
In this case, data often used on secondary storage systems (such as hard drives or SSDs) is temporarily stored in RAM, which you can access faster through the CPU.
Because RAM is more expensive (but faster) than secondary storage, disk caches are smaller than hard drives or SSDs.
Types of Cash Memory
The part closest to the CPU core is sometimes called the primary cache. However, this term is not commonly used.
Secondary cache This often refers to an additional piece of cache memory located on a separate chip near the CPU’s motherboard. This term is no longer commonly used, as most cache memory is now located on the CPU dye.
Cache memory levels.
Advanced computer systems have more than one piece of cache memory, which is closer to the cache size and processor core and, therefore, faster.
The smallest and fastest cache memory is the Level 1 cache or L1 cache, and next is the L2 cache. Most systems now have an L3 stock and since the introduction of its Skylake chips. Intel has added an L4 store to some of its processors.
To speed up access to frequently used instructions and data, Cache Memory stores them on the same chip as the CPU itself.
As a result, the CPU does not have to wait as long for sluggish memory accesses from main memory.