Not sure which specific change caused it, probably the various iterations of AnKors blue triangle killer mod (get the latest 1.5 version!), but I always used to use High Performance for the Texture Filtering option in Nvidia control panel as that seemed to help performance. Now it seems I can switch to the top end - High Quality - and everything still runs smooth and looks better than ever. Try it for yourself and let me know what results you get, please.