CPU Usage 100% -0%, 100% - 0 - Like a sine wave

[dcshaker]

Has anyone seen an issue in Windows 7 where my CPU usage goes from 0 to 100 then back and forth, like a sine wave? I had no apps running. If I reboot it becomes normal again. Ive tried to replicate what I was doing when I noticed it but nothing was found. This has happened 3 times in the last week. A pic of my Task Mgr illustrates.

 

[brianzion]

hi and welcome to the forums

if you download this program and run it you will be able to see in very concise view all your running processors Process Explorer v15.13 By Mark Russinovich

LINK >>> Process Explorer

introduction

Ever wondered which program has a particular file or directory open? Now you can find out. Process Explorer shows you information about which handles and DLLs processes have opened or loaded.

The Process Explorer display consists of two sub-windows. The top window always shows a list of the currently active processes, including the names of their owning accounts, whereas the information displayed in the bottom window depends on the mode that Process Explorer is in: if it is in handle mode you'll see the handles that the process selected in the top window has opened; if Process Explorer is in DLL mode you'll see the DLLs and memory-mapped files that the process has loaded. Process Explorer also has a powerful search capability that will quickly show you which processes have particular handles opened or DLLs loaded.

The unique capabilities of Process Explorer make it useful for tracking down DLL-version problems or handle leaks, and provide insight into the way Windows and applications work.

 

[dcshaker]

thanks, I have downloaded and will see what happens when it occurs again.

 

[dcshaker]

Well, its happeded again and I ran process explorer but still couldnt figure out what was causing the cpu usage going up and down.

 

[brianzion]

if you open the cpu graph inside the procexp and leave it running at the peeks on the graph run your mouse cursor over and it will show what process is at that point

 

[dcshaker]

Thanks, I'll do that next time. Pretty wierd though.

 

[dcshaker]

Its happened again. I checked and the process that is running is "interupts" - Hardware Interupts - DPC's. Im not a geek so I dont know what that is or why its happening.

 

[brianzion]

An interrupt is a message from a device, such as the keyboard, to the CPU, telling it to immediately stop whatever it is currently doing and do something else. In general, a very high rate of interrupts might indicate a disk or a network adapter that needs upgrading or replacing. Test your components and rule out a hardware problem.

can you post a screenshot of process explorer and right click on interrupts and click on performance graph tab and screenshot this please.

 

[dcshaker]

Here is the interupt and performance graph

 

[brianzion]

yeah should not be that high check all your devices external hard drives mouse keyboard usb wireless adapters etc leave the procexp running and the performance chart and unplug devices to see if it drops down; check all drivers for updates

An interrupt is a message from a device, such as the keyboard, to the CPU, telling it to immediately stop whatever it is currently doing and do something else. In general, a very high rate of interrupts might indicate a disk or a network adapter that needs upgrading or replacing. Test your components and rule out a hardware problem.

 

[brianzion]

go into Device Manager or devices and printers section and check for driver updates on every hardware component listed just finding a tutorial for you to do this if you are unsure

 

[brianzion]

updating driver in windows 7 using devices and printers section

 

[brianzion]

and a little more information for you at this link >>> Device management - Windows 7 features - Microsoft Windows

 

[dcshaker]

Ok, but the only thing I can shut down is the wireless router and printer. Its a new laptop (6 months or so) with nothing external attached but a printer.

 

[brianzion]

ok right sorry i took for granted it was a desktop Please fill in your specs here >>> http://www.sevenforums.com/profile.php?do=extra to help determine what may be the issue.

you could detatch the printer to see if this is the cause

 

[brianzion]

a program to help you fill in system specs >>> speccy Speccy - System Information - Free Download