Cache memory is a very important invention in the history of computation. Development in this area has helped processors reach higher speeds and be efficient in computing. Every computing device like a mobile phone in your palm or a personal computer has at least some amount of cache memory for efficient operations.
At first, every kind of memory was expensive and slow at the same time, and processors were slightly faster but the gap between their speeds was narrow. But the fast development of processors made this gap more wider, with rising clock speeds of CPUs older style memories could not keep up with them. So inherently it was very clear that a faster kind of memory was due to continue this innovation in computing keep growing. Otherwise, processors fast have to wait longer in order to receive the data or instructions that arrive from memory to the CPU, during this time CPU stays idle and it is a waste of computing power.
So, today almost every type of processor has a cache memory, be it a small or a very powerful one.
How Does Cache Memory Work
We can think of them as a small chunk of memory but very fast that resides inside the processor to keep feeding it resources, and what to execute next. It contains the instruction that will be executed next by the CPU, there are complex algorithms to decide and predict that.
So it basically loads important instructions from the main memory which is RAM or lower-level cache memories. One question will definitely pop into mind that, even once in a thousand times it will happen that the next instruction which should be executed is not in the cache memory, so the CPU has to do some more hard work in this case to fetch the next instruction form the main memory, this is called cache miss in technical term.
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Multiple Levels of Cache
But today modern CPUs use multiple levels of cache, L1, L2, and L3. Where L1 is the fastest in access time and smallest in memory capacity, and L3 is the largest in memory capacity and slowest among the three. So in case of a cache miss L2 comes into play and instruction is searched here, if data is also not found here searching is done on L3 and then after another miss search is done in the main memory. This will definitely make the CPU wait longer and the execution of the process will be much slower in this case.
Using a three-level cache system really makes difference, in modern processors from Intel or AMD have a hit rate of more than 95 per cent. So the chances of not finding instructions in the cache are very low.
Between Processor Speed and Higher Cache Memory
The answer is not that straightforward forward let me explain. you definitely had this question in mind what to choose between processor speed which is measured in GHz and more Cache memory?
To increase the performance of your laptop or your personal computer, both cache memory and processor speed are important. Speed in GHz, more speed results in faster execution of instructions. This means the time between two T-states is much lower. And more cache means more instructions can be loaded into the cache memory so that the CPU doesn’t have to sit idle. It can feed the next instructions much faster and more efficient way.
So things are quite related, both in a system in the right amount is necessary otherwise you will notice bottleneck. So depending on your workload, you should choose the right amount of Cache memory or speed. But definitely, you can’t choose like that, every processor has different configurations of cache and speed so it will change with the right amount of cache and speed according to the CPU you will choose.
A faster CPU will have a higher amount of cache and clock speed.
Difference Types of Cache Memory and The Difference Between L1, L2, and L3 Cache
There are trade-offs and benefits of this multilevel cache, and we can divide it up into three characteristics: capacity, access time, and cost.
- L1 which offers faster access time, and cost per bit is higher, and less amount of capacity
- L2 which offers greater capacity and also fast access time with a lower cost per bit
- L3 offers more capacity than L1 and L2 but has slower access speed and lower cost per bit
Cache memory resides inside the CPU and comes under the Inboard memory category with registers and main memory.
So right amount of cache memory is used as per the cost of the CPU as using too much cache memory will significantly increase the price of the CPU, so as per the need of the CPU cache memory is chosen.
How Much Cache Memory is Present in Modern-day CPUs
It basically depends upon the processor, so depending upon the processor it will vary. The CPU I have in my computer is Intel I5 – 12500H which has a 1.1 MB L1 cache, 9 MB L2 cache and 18 MB L3 cache which is good for today’s standards.
A lower-end CPU will have less cache than this. But around this configuration is considered good for ample performance which will not create a bottleneck in the CPU.
If you have a windows laptop and you want to check your cache memory in your laptop you can open your taskbar by pressing ESC + Shift + Ctrl key simultaneously or by right-clicking in the taskbar area and opening from there manually.
Notes
- Cache memory entirely should not be the buying factor for your CPU, a balanced approach between every component is good, and depending upon your workload you can choose.
- Depending upon your processor cache memory will increase or decrease.
- More cache memory or clock speed does not translate into more performance always.
Conclusion
You have already guessed that cache memory places an important role in a computer system, and we can safely say that without it modern computers would be much slower. Faster and more powerful processors have more cache as they can execute faster and need more instructions on the cache.
Hopefully, we are able to clear up your confusion about how much cache memory is required. If you have liked the article please share it with your family and friends and do correct us or leave your feedback in the comments below. Hope to see you next time, signing off.
