I needed a PC to test a PCIe card recently, so I put something together with some spare parts. The only PSU I had around was a corsair CX750M I took from a prebuild from about 2014-2015, one with the green labels. Searching around the internet I see loads of people saying not to buy them, but what about one I already have? How bad really it is? Will it fry my motherboard or burn my house down? Or is it just inefficient?