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CPU seemingly stuck at 2.49 GHz since Jan. updates

eelpout

Member
Here we go again.

Was wondering why my battery life hasn't been so great lately (around 5:15 hours). Checked the Task Manager and my CPU seems to be pegged at max speed, 2.49 GHz. I went to check the minimum processor setting under the Advanced Power settings and guess what, there are no more settings for processor min & max. They've disappeared.

I'll do the powercfg.exe reset and see if that fixes it. Sigh. :(

Edit: still can't change the min/max in the control panel (though I've found the registry entry). CPU-Z says the processor IS being throttled down. So I guess it's Task Mgr that's messed up.

CPU speed Capture.PNG

Poewr Settings Capture.JPG
 
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jrapdx

Member
Here we go again.

Was wondering why my battery life hasn't been so great lately (around 5:15 hours). Checked the Task Manager and my CPU seems to be pegged at max speed, 2.49 GHz. I went to check the minimum processor setting under the Advanced Power settings and guess what, there are no more settings for processor min & max. They've disappeared.

I'll do the powercfg.exe reset and see if that fixes it. Sigh. :(

Edit: still can't change the min/max in the control panel (though I've found the registry entry). CPU-Z says the processor IS being throttled down. So I guess it's Task Mgr that's messed up.

...
Very interesting! That exact number, 2.49, has been the CPU speed displayed on my system as well. However, I know exactly what happened.

In the default configuration, when running in "balanced" or "power saver" plans, when quiescent the CPU speed would settle at 0.75 GHz, and as loaded it would momentarily rise to 2.6 GHz or more.

Fine and good, but I wanted to use the Hyper-V virtualization technology MS kindly included with the SP2. Activating it (Programs and Features / Turn Windows features on or off) was quite the production and requires restarting the machine, like after a major update, so I guess significant changes are made to the system.

After reboot, task manager shows CPU speed to be a constant 2.49 GHz. Deactivating Hyper-V, the SP2 once again shows the default CPU speed behavior.

Maybe you could check what features are activated on your machine. Turning off anything you are sure you don't need might be enlightening.
 
OP
E

eelpout

Member
Very interesting! That exact number, 2.49, has been the CPU speed displayed on my system as well. However, I know exactly what happened.

In the default configuration, when running in "balanced" or "power saver" plans, when quiescent the CPU speed would settle at 0.75 GHz, and as loaded it would momentarily rise to 2.6 GHz or more.

Fine and good, but I wanted to use the Hyper-V virtualization technology MS kindly included with the SP2. Activating it (Programs and Features / Turn Windows features on or off) was quite the production and requires restarting the machine, like after a major update, so I guess significant changes are made to the system.

After reboot, task manager shows CPU speed to be a constant 2.49 GHz. Deactivating Hyper-V, the SP2 once again shows the default CPU speed behavior.

Maybe you could check what features are activated on your machine. Turning off anything you are sure you don't need might be enlightening.
Hmmm. OK. I'll check on Hyper-V settings. Maybe that's what's hiding the processor state adjustments from the power control panel as well.

Edit: yep, it was Hyper-V being enabled. Thanks!
 
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jrapdx

Member
Hmmm. OK. I'll check on Hyper-V settings. Maybe that's what's hiding the processor state adjustments from the power control panel as well.

Edit: yep, it was Hyper-V being enabled. Thanks!
Great! Glad that worked out.

I should have added that even with Hyper-V enabled, if I wasn't actually running the OS in the VM (in my case, FreeBSD), I didn't see a major impact on battery life. According to powercfg /batteryreport, the estimated overall battery life is 9:37, to me that's not bad at all.
 

beq

Member
This was the reason I had uninstalled Hyper-V as well, although IIRC someone here later explained that the CPU should still be throttled in actuality.

If you guys do find normal battery life (despite what Task Manager says about CPU running full boost), then perhaps it's also safe for me to re-install Hyper-V...?
 
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eelpout

Member
This was the reason I had uninstalled Hyper-V as well, although IIRC someone here later explained that the CPU should still be throttled in actuality.

If you guys do find normal battery life (despite what Task Manager says about CPU running full boost), then perhaps it's also safe for me to re-install Hyper-V...?
CPU-Z indicates that with Hyper-V enabled, the CPU still is being throttled.

Oddly enough, removing Hyper-V broke my idle sleep again. :(
 

jrapdx

Member
Wow. How are you getting 9:37 and I get 5:25?
No special magic at work, just a cautious approach to reduce power usage. The usual things apply: minimizing the number of processes running, turning off most GUI effects, use power saving options and as much as possible, when on battery power avoid running graphic-intensive programs. In real-world use, I'm rarely doing things on the computer continuously throughout the day, and having the computer sleep (or hibernating, even shut down) when idle reduces battery drain considerably.

No secrets there at all, it only takes some attention to what we're doing to reap the benefits.
 

jrapdx

Member
If anyone reading this post is curious about Hyper -V you might find this link interesting
5 excellent uses of Windows 8 Hyper-V | Virtualization - InfoWorld
I've been using Hyper-V since getting the SP2, in fact, it's one of the reasons I bought the SP2. The idea is running an OS like FreeBSD in Hyper-V, allowing remote development/maintenance of programs which run on unix platforms. At this point most of the kinks are worked out. Connecting to a server running in the VM from the Windows host, in the web browser it looks exactly like it does over the internet. That is impressive.

The last part of the article presents a very interesting idea, using a VHD as a boot partition for a "guest OS", and adding that VHD to the boot menu. I wasn't sure if this would work the same way with Windows 8.1/SP2. I will try to find out more but if you happen to have a pointer to such info, that would be very helpful.
 

Moodi

New Member
i have the 4200 u CPU ,i was wondering about the command that shows me how long windows was up since i started my machine? the task manager is showing me a combined number.
 

olimjj

Active Member
.The last part of the article presents a very interesting idea, using a VHD as a boot partition for a "guest OS", and adding that VHD to the boot menu. I wasn't sure if this would work the same way with Windows 8.1/SP2. I will try to find out more but if you happen to have a pointer to such info, that would be very helpful.
Yes. Even though I have not to date found occasion or need to use that idea, I also found it interesting and a potential future application.
 
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