Yea, it'll work fine but at reduced functionality, your motherboard specifications page will list the differences from using a 3rd generation processor and a 2nd generation processor. For example, on the Crosshair VIII, the following differences are highlighted:
![](/skins/images/642D505A1A051956CE376BACC711140C/responsive_peak/images/image_not_found.png)
![](/skins/images/642D505A1A051956CE376BACC711140C/responsive_peak/images/image_not_found.png)