NVIDIA GT740 SC ISSUE.

Hi,

i've installed El Capitan (motherboard Gygabyte z97x-UD3H-BK with GPU Geforce GT 740 sc 4gb ddr3. Installation works fine, but when I restart to make postinstallation with Clover, a gray screen appairs with a "drawbar" indicating the load process; after some seconds loading ends and computer goes to stop.
I think I should load a driver for GPU at the start with clover, but I dont' know how.

Someone could help me?

Thanks,

Luciano