While playing a game few hours ago I noticed my computer suddenly became incredibly slow. The windows task manager showed that the cpu was using half its capabilities. I have been playing this game since 4 years, with this same 4 years-old laptop, and it had never happened before. I have to mention I installed windows 10 few days ago, which also changed my graphic card's drivers. I suppose it is a feature preventing CPU overheat. It may be a new feature, changed parameters that enables it sooner than before, or dust accumulating past 4 years that activates it sooner than before as @Bokan's answer suggest.
The problem is that this feature does not get disabled when I quit the game, making the computer unusable for several hours. When I first posted this question I had to wait about 8 hours before it came back.. by itself. The only other way to get this speed back is to restart windows in any safe mode, but that is not very satisfying. I have checked battery and power parameters, they are not changed and changing them does not restore the cpu speed. I have checked the graphic card's parameters, same.
What is this feature ? How to disable it or change its parameters ?
NOTE : I have an intel CPU that has the SpeedStep technology. But the normal speed is not back after reboot (as I read it does when SpeedStep reduces it), I do not see any option to enable/disable it in the BIOS, neither on the GPU desktop UI. Last time the normal speed was restored while the computer was active (see comments).
EDIT : I just completed the first reboot of the second time this problem appears, and this time it disappeared ! This is madness.
This question has also been asked on answers.microsoft.com :
You can admire how microsoft does not care about giving the **** name of this feature to its unanimous customers, not even mentionning speedstep or battery / power / cpu parameters.
Also on other website, mentionning speedstep :
Here on SuperUser but does not solve my issue :
- What regulates Intel SpeedStep CPU throttling? Can I get some control of this on Windows7?
All my battery parameters, graphics parameters, power parameters are set to maximum/high/100%
On 'Answer Tech', live Microsoft's technicians all answer the same epic crap (they all prefer blaming the manufacturer, asking the customer to return his computer (!!!!) than answering that they do not know). This one was particularly good :
Best Answer
Having a "balanced" power scheme is not the issue.
It allows your CPU to downclock, go to 100%, and even turbo boost if needed.
If your CPU speed is halved, it may mean:
The CPU is thermal throttling.
Intel's XTU utility can help you check this.
Your laptop feels like it's on battery power, yet you have AC on.
Try removing your battery (you should remove it anyway when using from AC!) and try again.
Check if your power profile is really what is should be.
Like "Maximum" is really 100%.
Sometimes turbo boost can cause throttling or issues on poorly cooled laptops, you can disable it by setting 99% in the Balanced power profile. It will still run your CPU at it's max clock speed, yet will not use Turbo Boost. It's also a great way to have a cool and fast laptop, minus the loud fans. I do this all the time on my laptop - because plenty of apps just waste CPU cycles for no reason.
Applying the latest BIOS can also be a good solution.
Just make sure you have your battery in the laptop, and it is charged > 60%.