I have your X8SIL-F with website Bios 1.0C and Xeon L3406 CPU(Stepping SLBQQ),during POST I get the following BIOS error:
" Warning: This CPU is not supported"
But on your website productpage , I can see L3400 series type CPU's should be supported?
We indeed do support L3400 series type CPU's, this is a Bios problem,if website carries a newer bios, please take that one, if not than please request a bios from our technical support department, please request a bios called"x8sil_t3230"