How to make debian faster?
 

I have Debian 9 Stretch 64-bit, and sometimes it gets slow, how can I make it faster?

What hardware are you running it on? Processor? RAM?

Well, the first step is to make a descriptive and diagnostic survey of your machine. You should want to know what you use it for, what it has, and how everything is operating to make a start.

What have you done to try to determine WHY it gets slow? When does it get slow, and what all is running when it is slow, and when it is not? Have you examined the log files with an eye to finding out if there are entries related to the performance?

let's start with:

then post ouput of:

I've always found that getting rid of the gui speeds things up.

Building on what AwesomeMachine said, what desktop environment are you using?