Windows 10: Howo the base speed of my CPU can be lower than half of reported value?

In my computer the CPU is Intel i7 1255U with reported base spped of 3.5 GHz but in task manager and in dxdiag command I see 1.7 GHz. How is this possible, how to solve the issue?

:)

 

CPU speed much lower than base speed

My computer has been slow for quite a while now even while performing basic tasks such as web browsing (to the point where simply typing into a search bar can take several seconds before the computer shows me that I've typed anything) and I've finally gotten around to trying to search for a solution. I noticed that the speed listed on the performance tab of task manager is significantly lower than the base speed listed there (0.78GHz vs 2.59GHz) See here I suspect that this may be largely what is causing my problems.

I have tried the following things to bring this speed closer to my base speed:

• Moving the power management slider to "Best performance" See here
  
• Increased the minimum processor state when plugged in to 100% See here
  
• Turned off Speedstep in my Bios (which is described in the BIOS as forcing my CPU into its maximum performance mode
  
• Turned off C-states in my BIOS which is described in the BIOS as allowing the processor to be put in other performance modes
  

Notably I have been trying the fixes recommended in this thread: Maximum Processor Speed Lower Than It Should Be

Any advice on steps I can take short of reinstalling Windows is greatly appreciated!

System details:
Dell Latitude E7450
Intel Core i5-4310U CPU @ 2.00GHz 2.59GHz
8.00GB RAM
64-bit OS and processor

 

processor speed!

The applications report what the API (Application Programming Interface) returns, but in reality that value has no bearing on what the CPU really is. They report the value accurately, but the value is not the actual CPU speed.



On Nokia's Symbian/S60 based phones, all applications that rely on the kernel HAL (Hardware Abstraction Layer) CPU speed value, will report only a fixed value (number) that Nokia has never bothered to set to the actual processor speed of each model.

 

Cpu running half speed

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 :

• windows 10 only use half of max cpu speed
  
• slow processing speed
  
• my pc is running rly slow after the windows 10 upgrade
  
• slow laptop after windows 10 upgrade
  
• cpu not running at maximum frequency
  

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 :

• lenovo
  
• tomshardware
  
• tomshardware
  

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 :