# Optimus Laptop - how to tell which gpu is being used?

## dman777

I have a Dell E6430 laptop that has intel chipset. It also is a Optimus laptop(verified in bios). The second GNU is  Nvidia GF108GLM [NVS 5200M].  I am using  Intel 8xx/9xx/G3x/G4x/HD Graphics.

My laptop has a Intel  i7-3720QM CPU @ 2.60GHz with 6 cores. When I run chrome, there are times where chrome will  spike the cpu to 150%. 

However, when I attach a external monitor through VGA.... I do not have this cpu spike from chrome at all.

I suspect the difference might be that when the Monitor hooked up through vga, the Optimums feature is kicked in and the other nvidia gpu chip is in use. To trouble shoot my issue with chrome and cpu spikes, how can I verify which VGA is in use when I have the vga monitor plugged in versus not plugged in? I checked  dmesg and did not see anything that helped me.

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## szatox

How 'bout 'glxinfo | grep render' ?

Renderer string might give you some hint.

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