cannot pass apple logo at 2nd restart

Processor : Xeon X5450 LGA 771 modded to 775 Mobo : Gigabyte GA-EP43T-S3L Ram : 4GB DDR3 1333MHz x2 GPU : GeForce GT730

was able to install Sierra with these boot flags (it succeed only once out of many tries, i seem to forget one more boot flags): -v nv_disable=1 PCIRootUID=0 npci=0x2000 USBBusFix=1

after the first date region etc setup, it reboots. i manually get into the clover boot loader inside installation thumb drive. but ever since then, i can't get past the apple logo right after verbose ends.

i can't remember what is the missing boot flags i did on that successful installation. any idea?

I've tried npci=0x3000, -x.