phantom gaming 4 b550

So i have a b550 phantom gaming 4 motherboard which has 2 atx12v power connectors, but the power supply i have only has the 4+4 cable (rm650x) , is the extra 4 pin cable needed? Specs: Ryzen 5 3600 rx 480 B550 phantom gaming 4 2x8gb 3600mhz XLR8 RAM I apologise if any terminology is wrong

Me and my buddys parted together from people selling parts around for my PC. I bought a b550 phantom gaming 4 and a r3 3200g. Without thinking to look into cpu compatibility. Well long story short. The PC still somehow posts runs games fine and even Benchmarks near where it should wo/oc. That...