Warband lag

[Pitircinky]

Core 2 Quad Q6600 processor
AMD Radeon HD 6850 g card
4 GB Ram
Windows 7

I've played warband (75+ fps) before with same pc. When i change my motherboard its lagged. in village or out map screen there are lag even without npc.
I tried a lot of things. update to drivers, reinstall warband, install dx 11, format etc. Same fps at lowest setting and highest setting.

Thanks for help 

EDIT
I've just tried it with other games. highest setting in left 4 dead 2 working at 75 fps

 

[AleksanderTheGreat]

I would recommend checking what your rending method are set to? If they are set to directX 9, then switch to directX 7 for lower spec computers. See if that helps on your issue.