I'm Playing star wars battlefront 2, and on the in-game performance overlay, there are

                                             fps/ms
CPU
SIM
GPU

What is SIM? Mine is maxed out at 30/1.2 in-game. I presume that means 30 fps and 1.2ms lag
Why only 30 fps? Doesn't change with any video setting. The CPU and GPU are about 110 fps.

i7 6700k, GTX 1060

Please could someone explain the SIM number.