Russian player Dibie benchmarked the 0.9.7 performance on his PC (high-end i5, GTX 780) on a replay. The blue line represents the 0.9.6 client, the yellow line represents 0.9.7 client with minimap turned on and the red line represents the 0.9.7 client with minimap turned off. Left bar represents FPS, below is the time line of the replay.
As you can see, not only there is a drop in FPS compared to 0.9.6, but the minimap influences the FPS as well (positively). This FPS drop between patches is unexpected and Storm promised he'd investigate.