This PSU is the old 20 pin mobo power connector, whereas, my mobo is newer 24 pin female, found this adapter /extension male to female. You wouldn't think 20 to 24 pin conversion will do anything with power output?
All the extra four pins do is provide a few extra amps on 3.3/5/12V rails but are practically vestigial in nature. Now that the CPU and GPU have their own direct 12V feeds (PCIe and ATX12V power connectors) and most of what used to be add-in cards is now integrated in the chipset or CPU, the motherboard power connector does not need to provide anywhere near as much 3.3V/5V/12V power to add-in boards and CPU regulators as they used to.
If your motherboard has a 8pin ATX12V connector and your PSU only has a 4pin cable, you simply plug the 4pin cable in. The 8pin cable is not necessary unless you want to go for extreme overclocks.