Welcome to the fifth installment in the Be Your Own IT series, All About Computer Memory and How It Works. In this segment, we are going to talk about caching and how your computer uses it to make its performance faster and more efficient. In a previous installment, we discussed the different types of memory that a typical computer system comes with, and how the computer system uses a tiering process to determine when and how those different types of memory are used by the system itself. One of the types of memory that comes in a typical computer system that we listed were the Leve
Since your system RAM can often create a bottleneck when it comes to delivering data to your CPU as fast as your CPU can handle it, your computer system uses caching processes to try to alleviate the problem and keep your computer from locking up. Remember – if your CPU processes all of the information it currently has on hand and is not getting new information continuously, it will stop itself and sit around, waiting for new data to show up. This is obviously not very efficient, and even the fastest system RAM usually cannot deliver data and information to a modern CPU as fast as that CPU can process it, so that is where caching comes in.
There are two main types of caching set up to help your system along. Your Level 1 cache (also sometimes called the primary cache) is a very small amount of memory that is built right into your actual central processing unit. It does not have a lot of room – usually 64 KB or less. Your Level 2 cache is usually larger in size, but how large depends on the size of your CPU. This is also sometimes called the secondary cache, and it has a direct connection to your CPU, though it is not typically located in the CPU itself like the Level 1 cache is, though some high performance modern CPUs do have their Level 2 caches built in.
Caching uses a particular type of RAM called static random access memory (SRAM). It uses 4 to 6 transistors per memory cell and they do not have to be continually refreshed because they flip flop back and forth among themselves – each cell will maintain its data as long as it has power to do so, and since it does not need to constantly refresh, SRAM is very fast. SRAM is said to be synchronous if it matches the CPU's clock speed, so it is ideal to find SRAM that is synchronous.
The last component to your computer's memory is the registers. These are memory cells that are built directly into the CPU and they contain data that the CPU needs specifically, particularly the ALU (arithmetic and logic unit). It is controlled directly by the compiler that sends info to the CPU for processing. For more information on how your CPU works specifically and to learn more about the arithmetic and logic unit, see our article on how central processing units or microprocessors work.
And that about covers it when it comes to an overview of your computer's memory, the different types available, and what they all do. Remember that memory is an important and crucial part of your computer system – without it, your system cannot function. And when you don't have enough of it, your computer will not perform anywhere near as well as it would be able to otherwise. Ensuring that your computer has the right amount of memory in the right places ensures that you can use your computer without annoying delays and freezes, and be as efficient as possible.
