Guidance for installing a USB PCIe expansion card
Guidance for installing a USB PCIe expansion card
You recently purchased a Rosewill RC-508 USB expansion card to increase your PC's USB ports. You noticed it has a 4-pin Molex connector and are unsure about its placement. It seems likely it’s meant to connect to your power supply or a specific port on your motherboard. The manual doesn’t give clear instructions, so you may want to check the card’s documentation or contact the manufacturer for guidance on connecting it properly.
It's a newer setup with a modular PSU. I have a cable that should work, but I'm unsure about using it due to the three or four 4-pin connectors in series. My worry is whether to link the expansion card directly to the PSU or route it through the motherboard. I've noticed 4-pin Molex to SATA cables are a better option, so that seems more sensible.
Are you familiar with building custom PCs? For years, people have connected Molex devices to PSUs directly. No one has ever seen those unused connectors as an issue—they just aren’t needed. This is simple computer assembly; most people have done projects with one odd device using a Molex connector, and you run the entire cable. It’s been a common practice forever. If you’re concerned, you could manage with that setup, but it’s not something I’d include in a system I’d create.
You're following the right steps for your setup. The cable you linked is exactly what I needed to clarify my confusion. I was searching for a PSU cable with a single 4-pin connector and found several Molex to SATA cables. Your suggestion to use a 4-pin Molex to a 6-pin PCIe cable and connect it directly to the PSU is correct.