What is Cache Memory

What is Cache Memory and Function

So in this Artical we'll understand what is cache memory in computers and laptops. So in this Artical, we'll see what is the importance of this cache memory? 

What is the typical size of this cache memory ? what are the different levels of cache memory that we fight inside the computers?

So before we understand this case, from where it let us see different kinds of memory that we see inside our computers. So the first kind of memory that we find inside our computers is the non-volatile kind of memory like a hard Disk drive.

So this hard disk low contains a mechanically rotating fast disks, which is also known as platters.

And if you see any, commercially-available hard disk drive, the typical rotation speed of hard disk is either 5,400 or 7,200 RPM. So as hard disk drive contains a mechanical rotating part. So in terms of the speed, they are quite slow.

So the typical reader writes speed that you get with this hard disk drive is in the range of 80 to one 50 megabytes per second.

But if you see the clock speed of the CPU, it is in the range of one gigahertz up to the four gigahertz.

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So even though the processor is capable of accepting the data at much higher speed, but it cannot get the data through this hard disk divert, the same rate.

And that is where the second kind of memory comes from the DP. That is a random access memory.

Now these random access memory is faster compared to the hard disk trail. So this RAM can provider data to the CPU at a much faster rate compared to the hard drive, but still it is slower than the clock speed of the CPU.

So the typical speed of the RAM is in the range of 400 megahertz up to the 800 megahertz. Still, it is lower than the clock speed of the CPU.

But if you see the newer generation of the RAM like Didier three and Didier four, then they can operate at a much faster rate, like 1600 megahertz or up to the 2100 megahertz.

So now if you see the speed of these ramps, they are compatible to the clock speed of the CPU.



So now you miss it that these newer versions of RAM can supplier data to the CPU at the rate at which they want. The answer is No.

So the modern day processors, which we're using are not a single processor, but they are multi processors.

So this processor could be either quad-core or maybe even Octa core. So if all the cores are asking for data at the same time, then this RAM can not be able to deliver the data to the, all the calls at the same time. 

And that is where this cached memory comes into the picture. So this cache memory is fastest among the all memories. So now this cache memory is also, and that mixes memory, but it is a special kind of RAM, which is known as a static RAM.

So unlike the dynamic RAM, which we find inside the normal RAM, this steady RAM is quite, and the typical size of this casche memory is in the range of kilobytes up to the megabytes.

So the data which is frequently required by the CPU can be supplied by this cache memory who generally some instructions and some data, which is required by the CPU is stored inside this cache memory.

So now let us see the different levels of this cache memory. The first level of cache memory is known as a level one cache order, Elvin cache.

So in this case, the tiny amount of memory is integrated inside the CPU itself and all the cores inside the CPU Helder in New Zealand level one cache.

So as this level of one cache is integrated inside the CPU, so they can operate at the same speed of the CPU.

And that is the reason, the level one cache is fastest among the all caches. Now the typical memory size of this level of one cages in the range of 64 kilobyte.

Now inside this level cache, there are two kind of caches. The one is instruction cache, and the second is a data cache. So that instruction all the instruction, which is required by the CPU and the data cache stored their data, which is required by the CPU.

Now let us see the second level of cache. So this case is known as either labeled to cache, aura Alto cache.

Now this level two cache could be either inside the CPU or it could be outside the CPU.

Now this labor to cache could be separate for all the cores, or it could be shared between the, all the cores of the CPU. 

So if this level two caches is outside the CPU, then it is connected with a very high speed bus with the CPU.

So the memory size of this level to catch in the range of two 56 kilobytes up to the 502 kilobytes.

But in terms of the speed, they are slower than the Elvin cache on the third kind of cache is known as a level three cache.

So all the producers do not have this level three cache, but some higher end processors have this level three cache.

And this level three catches used to enhance the performance of this level one and level two caches.

Now this level three cache is shared among the, all the cores and it is outside of the CPU. It's the memory size of this level three catches in the range of one way up to the eight megabytes for high-end processors, but it is slower than the but still it is faster than the random access memory or RAM. 

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So now let us see the process flow when CPU need some data. So when you want to CPU need some data, then first of all, it will look inside the elven cache.

So if it will not find inside the element cache, then it will look inside the Alto cache.

So if the CPU finds the data inside the cache memory, then it is known as a cashier. But if data is not available inside of the cache, then it is known as a cache. Suppose, if data is not available inside of the ultra cache, then the CPU will look inside the random access memory or the RAM install.

If it doesn't find any data inside the RAM, then it will get the data from the hard disk drive. So when you are starting your computer for the first time, or you are opening some application for the first time, then that data will not be available in either cache memory or inner.

So at that time, though, CPU will get the data from the hard disk drive, but once the application is open and then after if it requires some data, then CPU will get the data either from RAM or through the cache memory.

Now, you may ask that if this cache memory is so fast, then by the size of this catchment where he's only in the megabytes.

So the reason is that this cache memory is much, much costlier than the other memories.

And that is the reason you will find only a few megabytes of cache memory, insider CPU.

So when you are, you're buying some desktop or a laptop for yourself, not only look the random access memory, but also look how much casche memory that CPU has because this cache memory besides the oral performance of the processor and the same thing is applicable for the smartphone processor as well.

So I hope in this Artical, you understood what is the cache memory and what are the significant loops cache memory inside of the computers.