Super User is a question and answer site for computer enthusiasts and power users. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

I have a i3 based system running Windows 7. I have noticed that even during intense activities like copying GBs of data the CPU doesn't exceed 25%. I have no malware.

Some questions based on that observation.

  1. Is that kind of usage normal for such an operation? I haven't done any major 3D rendering and such so I wouldn't know if the CPU might be used closer to 100%. Would it?

  2. Isn't there a way to speed p a long operation by assigning only that to one of the cores and letting other cores do the regular chores?

  3. Is it just a fact that most of us have computers way too powerful for any of our need and CPUs will be inevitably underused?

share|improve this question
For an everyday application that does use all of your CPU, have a look at 7-zip ( ). Compressing/decompressing big files with it, you should see your CPU at 100%. – schnaader Dec 19 '11 at 19:20
Why exactly do you want your computer to use more then 20% of your CPU, if it does that, then your performance will suffer. Try running a more resource intensive program, your cpu usage will increase, copying a file is not CPU intensive its I/O intensive – Ramhound Dec 19 '11 at 19:38
"I have noticed that even during intense activities like copying GBs of data the CPU doesn't exceed 25%." How is copying data "intensive"? CPU cache = 100 GB/s, RAM = 20 GB/s, hard drive = 0.1GB/s. Also, the CPU doesn't really do much here. Compiling applications is an example of a CPU-intensive task. – Breakthrough Dec 19 '11 at 19:48 <== You wanna see 100%? Use this. – WernerCD Dec 20 '11 at 2:23
  1. 25% CPU usage is perfectly fine for copying files. The real bottleneck for this is the hard disk (or the hard disk controller), so it is not a CPU intensive task

  2. Windows automatically does load balancing.

    By the way, 25% could mean that you are using 100% of one of your four (virtual) cores.

  3. That depends entirely on what you are going to do with your computer.

share|improve this answer
i3 processors have 2 physical cores, but 4 virtual cores due to hyperthreading, so 25% is the typical number you'll see when a single-core application runs at 100% CPU. – schnaader Dec 19 '11 at 19:15
@schnaader: I did not know that the i3 had hyper-threading. Fixed. – Dennis Dec 19 '11 at 19:24
To be honest, I had to look it up myself and also was surprised they have :) - is a good source for this. – schnaader Dec 19 '11 at 19:34

Of course in your example like others have said, what you see if simply because copying files is a hard drive's job, not a CPU job. But the other factor explaining apparently low CPU usage is having multiple cores.

Consider the following example, albeit extreme, of our server at work. It has 8 real cores which are hyperthreaded, totalling 16 virtual cores. Here's the result I get while compressing a big ZIP using one core only:

enter image description here

As you can see, it shows only 7% of total CPU usage, yet the core #3 that is working on it is obviously working at 100%! The reality is that this CPU cannot perform that single task faster, but it has extra parallel power: it could do a bunch of this task at the same time without slowing down an inch!

To view your CPU usage by Core in Task Manager, click on View...CPU History...One Graph Per CPU.

share|improve this answer
16 cores, drool, drool. – Moab Dec 19 '11 at 22:11

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .