Performance drop with FLIR

[netizensmith]

In 2d, on the ground, at night I'm showing 140fps. If I TDC right to get FLIR up on the MFD that drops to 90fps. Double TDC depress to get FLIR on the HUD and it drops to 70fps, so I've halved my performance by doing this. Bringing NVG up only has about a 3FPS impact.

 

Is this expected behaviour?

 

Thanks!