Normal GPU temps?

[theuserjohnny]

GPU= 37-40 degrees Celsius
GPU Diode= 37-40 degrees Celsius

So I was just checking out the temps and I've never really looked at either of the GPU temps.

I know that when I use the GPU I should expect them to spike but are these normal temps for the GPU? I would expect them to be lower since most of the time the HD4000 is the one being used to run everything.

Also difference between GPU and GPU diode?

 

[dusk007]

With the rMBP the HD 4000 is only in use if the dGPU is turned off.
If you have iphoto running in the back ground and otherwise do nothing but read text the HD 4000 is still off and the fast dGPU is in use. It is stupid but that is how Apple's NON optimus switching works because they just cannot get the drivers right and properly transparent.
You have to force the HD 4000 with gfxCardStatus if you really want good battery life and not waste it on a GPU that you only need for gaming.

Those are idle temps anyway. A GPU under load should be around 70C.