How to check which video card is active in a MacBook Pro?

Solution 1:

Assuming system_profiler will only report the active display (I'm not near a MBP to know) how about plugging this into GeekTool:

system_profiler | grep GeForce | sed -e 's/:/ /'

Edit:

If it lists the non active one on the same line as "display not connected" how about:

system_profiler | grep GeForce | grep - v "display not connected" | sed -e 's/:/ /'

If it lists the active one first how about:

system_profiler | grep GeForce | head -n 1 | sed -e 's/:/ /'

If active is second then replace head with tail.

Solution 2:

http://codykrieger.com/gfxCardStatus

This is a small app that resides in the bar and gives you not only the card in use but also the control over how and when to switch the card. For example you can set only integrated graphics card to run when on battery power - etc...