xeddiex :
Full pc spec please??
Are u having one of those older motherboards that has a 4pin power connector??
You should be able to split the 8pin cable into two 4pins.
My motherboard is new, and it has a 8 pin connector, my psu cable is also 8 pin but can be separated to two 4 pin. And one of the 4 pin fits with the connector but both dont.
Motherboard:asus prime b450m
PSU: Corsair VS550 550W (v2)