How does a dedicated gpu and an integrated gpu switch in a laptop?

[silentspeedz]

Hi, I recently bought a Lenovo Y50 and i've been trying to keep track of the GTX 860m temps but it's showing some weird results. I understand that when the pc is idle or when it's not running anything graphics intensive, then the gpu switches over to the intel hd. The question is, how does it manage to do that? Does the GTX 860m just completely turn off or is it still running in the background? I ask this because when I open MSI Afterburner, it shows the graphs constantly spiking from 0 to whatever the current state it. A bit difficult to explain in words.

Here is the screenshot of the graph on Afterburner (DURING IDLE):
http/gyazo.com/08e898b80dec32da1b2d2ec76a28a428

Notice how the graphs are spiking as if it is having a hard time detecting the gpu OR the gpu is turning on and off every second. Can somebody please explain to me why this spike is happening on idle?

Here is a screen shot of HWMonitor (not detecting GTX 860m or integrated gpu(?)):
http/gyazo.com/5648c50d6fe1f75b30b2ee9f9c810e8f

Thanks in advance!

 

[velo3100]

The most simplest way is to use the nivida control panel. Choose a program and select the gtx 860 and then open the program. Then open hwmonitor and it should detect it.

 

[silentspeedz]

I've done that and it does indeed detect it when I open HWMonitor while a game is running. My question is, how does it work when it's not using the gtx? Does the gtx run in the background while the computer is idle and uses the integrated intel hd? Or does the gtx completely shut off when it's not in use?

 

[velo3100]

Normally yes. The dgpu will turn completely off and you should be able to see that in the hwmonitor as it will only detect the igpu.

 

[silentspeedz]

Okay thanks for the reply!

If that is the case, then why does my Afterburner display those graphs in the screen shot? It constantly spikes as if the gtx is turning on and off. The screen shot of the afterburner graph was when the computer was idle. Can you explain why the graph does not STAY at 0 but instead spikes every second?

 

[velo3100]

Maybe its being used for your nivida geforce experience. It uses the dgpu to start the program up and that maybe why it is showing it like that. Apart from that, I am not really sure.