The max CPU load for your server will depend on what package you have and the resources allocated. Technically speaking, you could use your server up to 100% usage, but if you suddenly had a spike in traffic to your site, you could be looking at trouble. Everything would crash if you were already running at 100% full capacity.
We highly recommend trying to keep resource usage under 50%. It's encouraged to use no more than 60% of your current services resources for fluctuation and optimization. If you're running higher than that, you should contact us to talk about upgrading.
What Can Cause My Server To Crash?
The 3 main resources used regarding a server and what may cause it to stop functioning or crash if too high are:
CPU Load: CPU has two main uses. The first use is to accumulate the overall processing of the system. When the CPU usage is above 70%, the user may experience lag. The second use is to accumulate how the processor is shared between computer programs (what is currently running on the computer, back-end, and/or front-end). High CPU usage by a single program may indicate that it is highly demanding of processing power and maybe the reason for a crash. An example of the processor crashing is if your code, for a website, had an infinite loop running. You can check your CPU Load with the "top" command or within a WHM instance if you have the provided license.
Ram Load: Random-access memory (RAM) is a computer data storage that stores data and machine code currently being used on your machine. A random-access memory device allows data items to be read or written in almost the same amount of time besides that of the physical location of data inside the memory. RAM can be used from a website, for example, by running java-script from your computer within the front-end of things. RAM itself on the server can temporarily hold and send the required information to be processed from the person browsing your website. However, if your website experiences high traffic, this amount of requests to browse your website can crash your server. You can think of this from the launch of any big multiplayer game. During the hype, many people try to access the server, and the amount to process at one time may exceed the amount of RAM available. Thus those playing the game may experience latency or the crashing of the server when logging in.
Diskspace: Not to be confused with RAM, disk space is the hard drive of your server. This is where all of your data is stored if and when your server is shut down. The amount of disk space is determined by everything that your machine stores, including the OS (Operating System), software/programs, folders/files, etc. Normally, you can review how much disk space you have used and how much is available depending on your installed OS. However, should the Diskspace ever be full or close to being full, your server can crash or not run a program as intended.
Please feel free to Open A Support Ticket with any inquiries. If your server is crashing, talk to us in LiveChat to have an opportunity to help you.