If you click upside the Performance Stats window, fps goes up, and downside, it downs.
While it serves as a measurement, even when it appears to be adjustable. The game will always try to go as fast as possible.
Is it natural to exploit it's functionality? FPS can be the biggest killers yet an friendly tool if used properly. The lowest setting mimics god-mode, where I can't be killed and stall time to regen. at the precise frame-rate. Which can be seen through the client side, I assume? In the past, I've use this method to shoot through walls and pass through obstacles.
This subject does make me sound delusional, feel feel to explain the difference between lag & fps if I'm misinterpreting it's meaning. Thank you.
Worst problem for me atm is low FPS. I play on 3 years old laptop on Xubuntu. When sitting in town, it's usually ~20 and when fighting, it's ~10, sometimes even less. Limiting the FPS to ~15 helps te keep it above 10 a bit. As sven said, adjusting FPS can be used to shoot through walls and some other things.