Most web hosting providers offer resource limits on their services. Understanding these resource limits can help you make an informed decision when purchasing or upgrading a hosting service.
Layman Explanation – “The Car Analogy”
I often like to use what I call “The Car Analogy” to explain CPU cores. I use a car to represent a CPU core and people being transported to represent website visits.
Single CPU Core:
Imagine for a moment that you have one car instead of one CPU core. One individual car (CPU core) can move people (website visits) from one location to another, and it is designed and intended for this purpose.
Let us also imagine that the car will always move as fast as it is capable of doing. You do, after all, want to get where you’re going as quickly as you can, right? Your one car can only move people so fast, and it can go no faster.
More CPU Cores and Speed:
Now, imagine you are not happy with the speed of your car and want to improve your transport system. You have the option to either upgrade to a faster car or buy another car like the one you already have.
Buying Another Car: Buying another car just like the one you already have will not cause either car to move any faster. The second car gives you additional capacity but does not increase transportation speed. You can move more people simultaneously, but no person will move faster than when you only had a single car.
Upgrading to a Faster Car: Upgrading to a faster car instead of buying a second car will get you where you are going faster. This means each trip is quicker, effectively increasing your transport capacity because you spend less time driving and more time waiting for the next load of people to transport.
Relating to CPU Cores and Website Visits
Single CPU Core:
One CPU core can handle a limited number of website visits at a time. If too many visitors come at once, the core can get overwhelmed, slowing down the website.
Just like one car can only move a certain number of people at its speed, one CPU core can only handle a certain number of website visits at its processing speed.
Multiple CPU Cores:
Adding more CPU cores means your server can handle more website visits simultaneously. Each core takes on some of the load, allowing more visitors to be served simultaneously without slowing down.
Just like having multiple cars allows you to move more people simultaneously, having multiple CPU cores lets you handle more website visits simultaneously.
CPU Core Speed
The speed of each CPU core affects how quickly it can handle each website visit. Faster cores process requests quicker, improving the overall user experience. Just like faster cars move people quicker, faster CPU cores handle website visits faster, leading to a more responsive website.
TL;DR
CPU Cores: More cores increase the number of concurrent tasks (website visits) your server can handle, improving concurrency. More cores do not inherently increase speed.
If you are exhausting your available CPU, adding more cores will restore lost speed but will not give you more speed than when you weren’t exhausting your available CPU.
CPU Speed: Faster cores process tasks (website visits) quicker, improving overall performance. You also gain more concurrency, although only in so far as tasks finish faster, meaning that your CPU core can then get to work on the next task sooner.