Simple syntax and the detailed snapshot of system resources makes top a common choice for identifying the CPU usage of the machine: $ top But, as you can see from the following picture, it can be a little hard to read.Generally speaking, the topcommand is the most popular choice for monitoring system resources. You can type top in a terminal to open it. The “top” and “htop” UtilitiesĪnother command, usually available out of the box on Linux systems, is top. These concepts of “free,” “used” and “available” are used in some graphical applications, too. This is what you can consider RAM that is actually free. That’s because as soon as an application requires more RAM, some buffer/cache data is instantly deleted to free up memory for your program.Ĭonsequently, the most important fields here are “used” and “available.” The first reflects how much RAM your programs are using, and the second how much RAM is available to applications that require it. That’s why if you open your browser, close it, and open it again, it loads much faster the second time.Įven though the buffer and cache may use almost all of your RAM, you can still consider that portion of memory free.

This way, when it needs to read the file again, it can skip accessing your slower storage device and read from the much faster RAM. That’s because of “buff/cache.” When the operating system reads a file from your hard-disk or SSD, it keeps its data in RAM. Here, “free” doesn’t mean the amount that your applications have at their disposal.

The output may be misleading for those coming from a Windows background.

Show cpu usage ubuntu