Solved 8.1 Pro idle CPU usage

updated: 8.1 Pro idle CPU usage when HDMI is used

Hey folks, I need your help troubleshooting here.

This is with a clean install of 8.1 from a MS ISO, downloaded and installed on Nov 14th. It is fully up to date.
This behaviour was not present with Windows 8, but I have done 3 clean 8.1 installs with the same outcome.

When I first power on my laptop, after windows is loaded, Core 0 on my CPU (i7 4700MQ) idles at around 90%, with task manager showing 11-15% CPU usage. System interrupts shows the most usage of all items on the list.



I have changed the minimum usage in power options to 5% for all power profiles. This behaviour is present under low power, balanced, and high performance power modes and doesn't change if I change them. (See http://www.eightforums.com/performance-maintenance/32041-windows-8-task-manager-4th-gen-i7.html ). In low power mode the usage is slightly less but is still present.

This processor usage continues as I run other programs, or as long as I let it idle without going to sleep.

If I put my computer to sleep, and then wake it, after idling for a short while..


all is as it should be!

I have the latest drivers for my chipset, GPU, WiFi, and Intel graphics (laptop has switchable graphics). This behaviour is present even with the OEM 8.1 drivers for these items.
All my other drivers are the ones released by my laptop OEM (Sager) in the last couple of weeks, specifically for 8.1.

There is a new BIOS that is being released by Sager (Clevo, which is the company that makes Sager branded laptops, has already released their "8.1" BIOS, I am waiting for the official Sager one though). I suppose this could fix it, however another fellow with the same laptop as me is not seeing this issue.

So...
anyone have any ideas?

Thx in advance

So, I figured something out today..

If I unplug my monitor from the HDMI to my external monitor, the usage stops! Also if I boot without the HDMI in, there is no mystery usage. ALSO if I disable and then re-enable the ATI HD8970m, the usage stops!

This laptop has switchable graphics between Intel HD4600 and the ATI.

Anyone ever seen this before?

Same Interrupts here. I just reinstalled my system with the 8.1 update from store, which was the first nightmare to bring it to work.
Without the latest Intel 4600 graphic driver, only the Windows standard graphic driver loaded, no Interrupts are shown in Task Manager. After installing the latest Intel driver System Interrupts are constantly using around 10 % CPU usage. Installing the Intel driver which Windows Update automatically would install ends up in a blank screen after logging on. Nightmare after nightmare. So I assume we have to wait until Intel comes up with a new 8.1 driver.

Ok, I found the culprit on my system.
It was an USB Controler. To be more precise: Intel(R) 8 Series/C220 Series USB EHCI#1 - 8C26
But at the first glance, it looked like the graphic driver caused the issue, cause there were no interrupts without the driver.
But my system protocol statet the system was unable to load some usb driver. But I have no USB troubles so far. Haven't tried USB 3.0 though.

Interesting, it seem it is the same on mine. No new drivers from Intel... I wonder if this will ever be fixed?

For now it might be best to set USB selective suspend to On in Control Panel > Advanced Power Options if it's not already set.

I set the maximum usage to 50%.

I was getting 99% usage always.

Now usage averages 40%.

I'll leave it there a while & see what happens.
Everything is running ok so far.

Windows Update installed a new Intel 4600 graphics driver two days ago, I figured it is version 3379. On my system, the interrupts are gone with this driver installed. It doesn't show the version number in the update window, it only says WDDM 1.3 or something, but device manager states Version 3379, which is newer than the latest driver in the Intel download center (up to now).

Hybrid Vigor said:

Windows Update installed a new Intel 4600 graphics driver two days ago, I figured it is version 3379. On my system, the interrupts are gone with this driver installed. It doesn't show the version number in the update window, it only says WDDM 1.3 or something, but device manager states Version 3379, which is newer than the latest driver in the Intel download center (up to now).

Click to expand...

CONFIRMED

After reading your response in my email, I tried this when I got home from work today. Fixed!

So, anyone having this issue, go to Device Manager, expand Display Adapters, right click Intel Graphics 4600, and click "Update Driver Software...", then let it look online for drivers.

Thanks for the heads up Hybrid!