Ok thanks guys, yeah my rig OLD, but i fixed it now. Temps are fine.
anyway, i have downgraded to 18.104.22.168. and installed iCEnhancer 2.0n
however, i had lower FPS but it feels a lot smoother than Vanilla.
Benchmark - settings untouched.
Average FPS: 18.07
Duration: 37.51 sec
CPU Usage: 56%
System memory usage: 54%
Video memory usage: 35%
after tuning settings (disabled AA), FPS goes up is around 20-30. not bad for an old Low End PC.
It ain't CPU intensive anymore. now it needs GPU power
Also my CPU and GPU temps became lower than before.