Details about your MSI B450 board
Details about your MSI B450 board
The extra four pins are intended solely for heavy overclocking. However, I don’t think they add much value here since the VRMs are likely to reach their limits before you hit the maximum of just the 8-pin EPS connector. In short, there’s no real performance gain, and you can safely leave it unplugged. Concerning the built-in audio, it should cover most non-expert headphones well. I have a comparable S1220 codec on my motherboard, and my Sennheiser Game Ones deliver excellent sound, especially compared to my previous setup. Overall, if you don’t own high-end headphones, the onboard audio should suffice.
You can verify this by visiting the boards' websites. The arbitrary names like "SupremeFX" are mostly just labels for the same component.