try this

creata a notepad

put these inside

WorldRender.SpotLightShadowmapResolution 256
RenderDevice.TrippleBufferingEnable 0
RenderDevice.ForceRenderAheadLimit 1
Render.DrawFps 1
WorldRender.FxaaEnable 0
RenderDevice.Dx11Enable 0
Render.PerfOverlayEnable 0
PostProcess.DynamicAOEnable 0
Render.DeviceVSyncEnable 0
WorldRender.MotionBlurEnable 0

then save as .cfg

tell me the outcome =]