FPS drop problem

[==Troy==]

System : Windows Vista

Hardware :
CPU : 2.4 Ghz dual Core
GPU : Geforce 8600 GT CDDR3 256MB
RAM : 4GB DDR2
Updated drivers

Game :
BA 6.5 DSD/other maps

Problem :
FPS considerably drops upon an explosion of a mine, roach bot, commander, or in some cases due to dgun usage.

FPS drops for 5-300 seconds after the event. Moving the screen to an empty part of the map sometimes fixes the problem. Zooming out/in sometimes helps too.

If the explosion happened outside of the viewport, FPS is not affected.


Edit : everything is set to lowest quality, besides the 3D trees and lua shaders. Turning them off did not help either.

[zerver]

Sounds like you have the problem caused by the "optimized threading" setting in the nvidia control panel.
Turn it off...