Cache Memory- JMD.pptx

cache memory

1. DULDULAO, JULIANA MEI A. Cache Memory (L1, L2, L3 & caching techniques)

2. What is Cache Memory? A cache memory is a very high speed, expensive piece of memory, which is used to speed up the retrieval process. Without cache memory, every time the CPU requests for data, it would send the request to main memory which would then be sent back across the system bus to the CPU. The idea of introducing cache is that this extremely fast memory would store data that is frequently accessed and if possible, the data that is around it.

3. Programs and apps on your computer are designed as a set of instructions that the CPU interprets and runs. How does Cache memory work? This is where the memory hierarchy comes into play. The data first gets loaded up into the RAM and is then sent to the CPU. CPUs these days are capable of carrying out a gigantic number of instructions per second. To make full use of its power, the CPU needs access to super-fast memory, which is where the Cache memory comes in. The memory controller takes the data from the RAM and sends it to the CPU cache. Depending on your CPU, the controller is found on the CPU, or the Northbridge chipset found on your motherboard. The memory cache then carries out the back and forth of data within the CPU.

4. The Levels of CPU Cache Memory: L1, L2, and L3 L 1 L 2 L 3

5. The Levels of CPU Cache Memory: L1, L2, and L3 L 1 Cache L1 (Level 1) cache is the fastest memory that is present in a computer system. The size of the L1 cache depends on the CPU. Some top-end consumer CPUs now feature a 1MB L1 cache, like the Intel i9-9980XE, but these cost a huge amount of money and are still few and far between. Some server chipsets, like Intel's Xeon range, also feature a 1-2MB L1 memory cache.

6. The Levels of CPU Cache Memory: L1, L2, and L3 L 1 Cache

7. The Levels of CPU Cache Memory: L1, L2, and L3 L 2 Cache L2 (Level 2) cache is slower than the L1 cache but bigger in size. Where an L1 cache may measure in kilobytes, modern L2 memory caches measure in megabytes. The L2 cache size varies depending on the CPU, but its size is typically between 256KB to 8MB. Most modern CPUs will pack more than a 256KB L2 cache, and this size is now considered small. When it comes to speed, the L2 cache lags behind the L1 cache but is still much faster than your system RAM. The L1 memory cache is typically 100 times faster than your RAM, while the L2 cache is around 25 times faster.

8. The Levels of CPU Cache Memory: L1, L2, and L3 L 3 Cache Onto the L3 (Level 3) cache. In the early days, the L3 memory cache was actually found on the motherboard. This was a very long time ago, back when most CPUs were just single-core processors. The L3 cache is the largest but also the slowest cache memory unit. Modern CPUs include the L3 cache on the CPU itself. But while the L1 and L2 cache exist for each core on the chip itself, the L3 cache is more akin to a general memory pool that the entire chip can make use of.

9. The Levels of CPU Cache Memory: L1, L2, and L3

10. Caching techniques What is Caching? Caching is a mechanism to improve the performance of any type of application. Technically, caching is the process of storing and accessing data from a cache. The main reason why caching was born is that accessing data from persistent memories takes a considerable amount of time. Thus, whenever data is retrieved or processed, it should be stored in a more efficient memory. Caching is a fairly simple way to achieve performance improvements. This is especially true when compared to algorithm optimization, which is usually a much complex and time-consuming task.

11. Different types of Caching

12. 1 Spatial Cache 2 Temporal Cache Spatial Locality means that all those instructions which are stored nearby to the recently executed instruction have high chances of execution. It refers to the use of data elements(instructions) which are relatively close in storage locations. Temporal Locality means that a instruction which is recently executed have high chances of execution again. So the instruction is kept in cache memory such that it can be fetched easily and takes no time in searching for the same instruction.

13. 3 Write-Through Cache 4 Write- Back Cache W rite-through data is simultaneously updated to cache and memory. This process is simpler and more reliable. This is used when there are no frequent writes to the cache. It helps in data recovery. A data write will experience latency as we have to write to two locations. It Solves the inconsistency problem. But it questions the advantage of having a cache in write operation. The data is updated only in the cache and updated into the memory at a later time. Data is updated in the memory only when the cache line is ready to be replaced. Write Back is also known as Write Deferred.

14. REFERENCES https://www.makeuseof.com/tag/what-is-cpu-cache/ https://techaudhary.com/what-is-cache-memory/ https://www.geeksforgeeks.org/difference-between-spatial-locality-and-temporal-locality/ https://www.geeksforgeeks.org/write-through-and-write-back-in-cache/