Massive FPS drop

RIOTSIDE

Reputable
Mar 10, 2014
11
0
4,510
ok system specs HD7850 FX8350 4.0ghz 8gb DDR3 1333mhz ram

Metro last light on low settings go from 100+ to 10 fps and stays

what is this issue
 

RIOTSIDE

Reputable
Mar 10, 2014
11
0
4,510
GPU-HD7850
CPU FX8350
Mobo - ASRock 990FX
Ram- 8GB corsair vengeance
Case- Thermaltake Urban S31 Snow Edition
Psu- corsair Corsair Gaming Series GS600
Casefans coolermaster 3x Cooler Master SickleFlow 120mm

Cpu stays around 18-25 idle and when playing Bf4 in ultra like 35-40
gpu around 20 idle and 40 playing a intense game