Oct 23, 2009

CPU 100% Busy

imageYou’re working along just fine then all of sudden your computer slows to a crawl. You wait and wait and then you wait some more. You take a coffee break and 3 hours later it is still crawling. Not having an IT Department to whine to, you fire up Task Manager by right-clicking on the Task Bar in an empty space.

When Task Manager appears, you go to the Performance tab and sure enough one of your CPUs is showing 100% usage. Now this isn’t that bad if you are launching a application (especially one like Visual Studio). But when it stays like that for the entire afternoon, you have a problem.  You think, well I’ll just pop over to the Processes tab, sort on the CPU column,  and see who the culprit is and kill that mudder-fracking-cpu-bogarting slime ball, just see if I don’t. The only problem is you get to the processes tab and you can’t find a culprit other than the System Idle Process and you sure as heck aren’t going to kill that.  What is going on?


image You may never find out, but there are some steps you can take to try. First get thee back over to the Performance tab and turn on the option to show kernel times (no this has nothing to do with fried chicken or popcorn).  Kernel time is basically time the CPU is spending doing OS calls, things like talking to the ethernet board, writing to the hard disk, monitoring all the typing mistakes you make on your keyboard, monitoring all your USB devices and so many other things it amazing you can actually ever get any work done on the computer. If that CPU bar turns red (and it will) that would explain why you can’t find a guilty process. Now you know where the problem is, the hard part is finding it.

image This scenario describes what happened to me. Your mileage may vary. I would come in, boot the machine and start working. Four to five hours later the CPU would slow to a crawl and I would quit everything and reboot. This got old after several weeks so I used the above process. When the problem next happened. I quit every program. Then I went to the services control panel and quit every possible service that Windows would allow me kill (this took a while). None of it did any good (I think you can skip this step). Then I sent to the Device Manager and I tried disabling every device I could. I stopped the Ethernet, USB devices etc. The problem didn’t go away. Then I suspected the Hard Disk. OK I failed to mention that a few times during the past weeks Disk Check ran on startup, I didn’t notice any problems but Windows was automatically running it so it did make me a little suspicious. This is not that old a computer and it had a Seagate Barracuda 300 Gig or so drive it that had a decent reputation. However, being that the economy needed some big spenders like me to prop it up I went to NewEgg and plopped down $50 for a new 500 Gig drive.  When it arrived I used Acronis True Image (I already owned version 10 – which I forced to work with Vista – but it will cost you another $50) to clone and replace the suspicious drive.  Really, you need to get a disk cloning tool. You don’t want to install a new drive and then spend a week reinstalling windows, all the service packs, patches and applications and rebooting 423 times, life is too short, just quit giving the kid’s an allowance for a while.  It’s now the end of the week and the CPU problem is gone.  Don’t worry I didn’t euthanize the old drive, I dropped it off at a barracuda rescue shelter that finds good homes that need paper weights.

About Me

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Tod Gentille (@todgentille) is now a Curriculum Director for Pluralsight. He's been programming professionally since well before you were born and was a software consultant for most of his career. He's also a father, husband, drummer, and windsurfer. He wants to be a guitar player but he just hasn't got the chops for it.