You need a processor that can support more PCI Express Lanes.
The following is an excerpt from Intel website for Intel g3930 cpu:

Expansion Options
Scalability  1S Only  
PCI Express Revision  3.0  
PCI Express Configurations ‡  Up to 1x16, 2x8, 1x8+2x4
Max # of PCI Express Lanes  16

NB. Some of these lanes will be used up by other devices e.g. SATA

Also, as in the previous comment, this is a Bitcoin forum not Altcoin!