After 40 min of working CPU stuck at 0.39 Ghz speed

[enesbajrami]

After 3 day ago added 4 gb more ram and changed Hdd with Sdd, today after 40min of runing pc start runing very slow when I open task menager i see my cpy worked only 17% installed burn in test software to see, all other component in testing goes to 100%, cpu its has so much lag. What to do??

specs
Dell inspiron 15 3567
ram 8 gb ( 2x 4gb )
ssd uv 400 kingston 240gb
cpu intel i3 6006U 2.00GHz

 

[Sohom]

go to power options... change to high performance; select plan settings under high performance and reset to default settings.

 

[jojesa]

Is the CPU always running at 0.39 Ghz?
If you run CPU intensive tasks does it speed up?
Does it change if you connect or disconnect the power cord?
What's your system temperatures?

 

[Pat Flynn]

Check your CPU temps, it could be throttling to prevent overheating. Use a tool like HWMonitor, just make sure you launch it as 'Admin' or you won't see all the the temps. For that CPU, if it's higher than 95 degrees it will begin to throttle. At 100 degrees, it'll probably be stuck at the speed you've stated, but at 105 it will shutdown (all temps in celcius).
If the temps are high all the time, my guess is that the CPU cooler was bumped during the install of the ram/ssd. This could have caused the thermal paste to separate or crack- a lot of OEM laptops use very cheap thermal paste that hardens and doesn't maintain any kind of moisture. When it dries then cracks, it loses nearly all thermal conductivity. If this is the case, you'll need to take your notebook apart again and clean both the CPU and the heatsink (with isopropyl alcohol- recommend 70% or higher), then apply a fresh layer of thermal paste. I'd recommend something decent like the Thermal Grizzly Kryonaut, Arctic Cooling MX-3, or Noctua NT-H1. These will last a very long time without drying up (5+ years).

 

[enesbajrami]

The cpu temp is 43 °C the speed doesnt change when plug/unplug adapter

 

[enesbajrami]

I cant open the cpu because still have service waranty, I called to the service center, they told me it can be operating system problem?

 

[jojesa]

I cant open the cpu because still have service waranty, I called to the service center, they told me it can be operating system problem?

Did it happen after a Windows 10 update?
Windows might be putting the CPU in its low power state, to save power. It does that by throttling apps and background processes.
Windows 10 it supposed to detect when it supposed to throttle, but I have seen that it may be buggy.
Plenty of times it does not work, so you can check on 'Task Manager' which app are marked for Power Throttling.
Press Ctrl+Shift+Esc to open 'Task Manager' then click the 'Details' tab.
Right-click the headings and click 'Select Columns' the select the 'Power Throttling' column.
Click 'OK' to save your changes.
Now you see a 'Power Throttling' column. It has information about each process’s power throttling state.

 

[enesbajrami]

I dont think so, I tryed live boot linux same speed cpu ( windows 10 installed / downlaed from piratebay )