CPU usage high at idle

Nicopolous · 02 Oct 2014

Hi all,

I've got a problem with my PC - I've searched high and low but can't find a solution - any help would be really appreciated.

When it's idle I noticed that my CPU usage was hovering around the 20% mark (I only noticed as I could hear my CPU fan speed up). As soon as I move the mouse to turn the (blank screen) screensaver off, the CPU goes back to 0% usage.

I'm trying to track down the offending process using Process Monitor (in particular the Event Profiling option). The process that is affecting my CPU is svchost.exe - which I know is the host for a number of services. I checked the PID and using Task Manager, checked what processes this particular one was hosting:

UxSms
UmRdpService
TrkWks
SysMain
PcaSvc
Netman
IPBusEnum
hidserv
AudioEndpointBuilder

I also filtered my Process Monitor log to see events that were logged to that svchost.exe. What I found was an entry for every single directory on my C and D drives - see the following extract:

svchost.exe
1136
CreateFile
D:\MY DOCUMENTS\My Music\Music\FLEETWOOD MAC\RUMOURS (EXPANDED & REMASTERED) - DISC 1
SUCCESS
Desired Access: Read Data/List Directory, Synchronize, Disposition: Open, Options: Directory, Synchronous IO Non-Alert, Complete If Oplocked, Open For Backup, Attributes: n/a, ShareMode: Read, Write, Delete, AllocationSize: n/a, Impersonating: NT AUTHORITY\SYSTEM, OpenResult: Opened

svchost.exe
1136
SetBasicInformationFile
D:\MY DOCUMENTS\My Music\Music\FLEETWOOD MAC\RUMOURS (EXPANDED & REMASTERED) - DISC 1
SUCCESS
CreationTime: 01/01/1601 00:59:59, LastAccessTime: 01/01/1601 00:59:59, LastWriteTime: 01/01/1601 00:59:59, ChangeTime: 01/01/1601 00:59:59, FileAttributes: n/a

svchost.exe
1136
FileSystemControl
D:\MY DOCUMENTS\My Music\Music\FLEETWOOD MAC\RUMOURS (EXPANDED & REMASTERED) - DISC 1
END OF FILE
Control: FSCTL_FILE_PREFETCH

svchost.exe
1136
CloseFile
D:\MY DOCUMENTS\My Music\Music\FLEETWOOD MAC\RUMOURS (EXPANDED & REMASTERED) - DISC 1
SUCCESS

I have no idea if this is normal!

Any help you can offer would be appreciated - I leave my computer on for extended periods and I really don't want the CPU sitting there at 20% usage with my HDD constantly being accessed!

Thanks,

Nick

Tookeri · 02 Oct 2014

Don't know what the logged events mean, but I think you may have a scheduled task that is set up to run when the computer is idle. If you can find that task you may be able to solve it. I don't know a way to find tasks that run when idle except to open every task and check its conditions and that's too difficult. But if you open a command prompt (cmd.exe) and run this you'll get a list of all running tasks:

schtasks /query | find "Running"

But chances are that when you run it after the computer is in idle, the task will stop. Put the code below in a text file and save it as .bat When you run it it will list all running tasks every 30 seconds, and it will include a time stamp too.

Code:

@ECHO OFF
:LOOP
TIME /T
schtasks /query | find "Running"
TIMEOUT /T 30
GOTO LOOP

And try Process Explorer, also from Sysinternals, instead of Task Manager. It's much better!

Nicopolous · 02 Oct 2014

Thanks for the reply, much appreciated :)

I actually worked out what was going on. There were two things happening which I was confusing between.

Firstly, I think the svchost.exe process was a normal Windows background check of something (not indexing but similar).

I also have WmiPrvSE.exe spiking CPU process to 2% every few seconds and constantly referencing tzres.dll. This is due to AVAST anti-virus and happens on all the PCs I have installed it on - so looks like I have to live with that!

Cheers