Bad frame rate since update 1.9.2

[Ashnurazg]

My frame rate decreased from time to time from 60 fps (@ 65-90% "CPU") to 20-40 fps (@ 100% "CPU") at v1.9.2 without a particular reason (vsync enabled).
A relogg helps to get the normal frame rate back. But should I relogg every time that happens (especially in fort battles)?

My system is good enough to play Regnum at 100-400 FPS, but it consumes much power, so I enabled vsync.

PS: Teleport is buggy, too. Some character will spawn IN the ground and cause extreme frame rate drops. I ask them whether they are in the ground, but they are not at their PC --> graphical bug.

PPS: Regnum is single threaded, doesn't it?
It will scale better on multi core system (nearly every PC today is a multi core system) if Regnum is multi threaded.