Computersight -

Without cache computers would be at least 100 times slower and maybe even slower than they are today. Cache plays a very important role in the computer world.

How does it work? See things this way, imagine you need a tool to make something, you are the processor and you send a message to the hard disk to send the tool. The hard disk is very slow compared to the processor so the processor has to wait while the hard disk is sending it to the RAM and then to the CPU and then finally the CPU can use it.

This process is super slow, this is why the first time opening the programs takes always the longest. Now with cache you can see that the time to open it is much slower because of the way of working. When you open a file for the second time, the CPU will first check his own cache to see if it has the files on it yet/already, then will check the RAM cache which is the second fastest thing, and only after that will check the hard disk cache and then the hard disk itself. You see, if the CPU or the RAM already have the files on it, the process is much faster.  However if it does not have the files, checking each one, one by one will take a lot of time compared with what would take to go directly to the hard disk.

Cache sometimes is good, sometimes is bad. The thing that makes your computer crash the most is the cache, specially a full cache.

Firefox when has it’s cache full will become much more slower and will crash more often. I know this should not happen ever because cache was designed to make computers faster not to make computers slower, it just so happens that the CPU will have to check all the time all the files in the cache and after that return to the hard disk and when you have thousands of files this is a very slow and painful process to the computer. This is why it’s very wise to clean your computer cache and to restart the computer from time to time to clear the cache and give it a fresh restart.