Hey Ugh,

On my system I notice a pretty large increase in FPS when I have only nameplates showing on the character I'm driving with instead of all five characters.
I run the driving character at 120 FPS and all others at 30 FPS in the background.

My system is not the best, only 64bit, I7-4790k @ 4GHZ. 16GB high performance ram, a 4GB GTX 970 as the main graphics card, with just a GTX 750TI dedicated to PhysX.

Obv. the more mobs that are on screen the bigger the performance draw from having nameplates showing on each character as well.