No it wouldn't, it would just be putting a temperature value in "empty" not putting particles with physics and interactions. I can't imagine more than a 5 fps drop at most.

Heat transfers.

And what is your fps drop calculation based on, and what system?

Yeah it does, that's why "empty" would need a temperature value.

I didn't make a calculation I made an estimation, I estimated based off of 45fps for a blank screen though so that would mean about 90% the original fps.

Could you rephrase that?

Certainly

In response to "heat transfers": That's why I was saying 'empty' needs to have a temperature value so it can be added into the heat transfer calculations without the need of simulating "air" as a particle.

In response to the question of FPS, I estimate it would drop the speed of a system with nothing on the screen running at 45FPS to 40FPS (90% the original speed).

My question was how did you estimate that.

Just a random guess at that point... but now I'll test it :p

I did this on my machine:

Filling the screen with diamond the screen is 20FPS, turning off heat it jumps to 28fps, 71% original to have heat calculations go across the screen. I was defiantly a good distance off on my original estimation (it would go down to 32 fps) but if it is ever added it is best added as an option, like the temperature compatibility mode now, since it would not only effect the speed but more importantly past simulations.