Why Is System Idle Process Consuming 99% of System Resources?!

Windows task manager (CTRL+ALT+DEL) usually shows that the “system idle process” consume as much as 98~100% of the system resource. What is it really doing and why is it using that much of the system’s resources in doing so?

What Is System Idle Process

First, a short definition of what a system idle process really is.

In Windows NT operating systems, the System Idle Process contains one or more kernel threads which run when no other runnable thread can be scheduled on a CPU. For example, there may be no runnable thread in the system, or all runnable threads are already running on a different CPU. In a multiprocessor system, there is one idle thread associated with each CPU.

The threads in the System Idle Process are used by Windows NT to implement CPU power saving. The exact power saving scheme depends on the hardware and firmware capabilities of the system in question. For instance, on x86 processors, the idle thread will run a loop of HLT instructions, which causes the CPU to turn off many internal components and wait until an interrupt request arrives.
[via wikipedia]

In short, that’s only all you need to know. It simply means that your computer is idle and not doing much work or at all, and in fact it’s helping you to save power and electricity at the same time. If you start doing something such as opening up a new browser session, music player, games or rip a Blu-ray movie, you will notice that the “system idle process” drops down significantly. In other words, it’s a good thing that “system idle process” remains at 98%-100% when you’re doing nothing, it’s sort of like the computer telling you that you have 98~100% of the system resources ready at your disposal whenever you want to start doing something on your computer.

Another interesting fact is that “system idle process” can only be found on Windows NT (meaning Win2000, XP, Server2003, Vista, Server 2008 and 7). You won’t find it on Windows 98 or Windows ME.

If you’re a computer geek, you might want to read the next page which talks about CPU idle time.