Consider using LP4 Molex for the P4 4-pin CPU adapter.
Consider using LP4 Molex for the P4 4-pin CPU adapter.
You're facing a common challenge with your setup. The x570 TUF gaming motherboard supports an 8+4 CPU connector layout, but your Ryzen 3900X likely needs more power than the single 8-pin cable can provide. Adding an adapter could help you connect to the empty 4-pin port without issues and simplify the overclocking process.
A) No, avoid using adapters to connect generator power from unsupported components.
B) The additional four-pin connector is unnecessary. You only require it for LN2 overclocking, which seems unlikely. The standard eight-pin CPU power can handle nearly 400 watts safely.
Running your 3900x at full settings will force all cores to run at the same speed, cutting off single-core performance. You'll be stuck at around 4.3/4.4 GHz and no core can reach its advertised top frequency anymore. On AMD, just follow @TofuHaroto's advice and turn on PBO. The extra heat and trouble keeping it stable aren't worth the loss of single-core speed.