I have an Enermax D.F. 650W fully modular power supply currently powering an RX 5700 XT with a daisy-chained PCIe cable. I'm considering upgrading to an RX 6800 XT, though I also briefly considered an RTX 5060 Ti. I no longer have an extra PCIe cable for the PSU and found a replacement cable listed for Enermax units, but I'm unsure whether it is genuinely compatible and safe. Can I run the 6800 XT using the existing daisy-chain cable, or should I buy a new power supply?
2 Answers
Do not buy a modular PSU cable just because the connector looks correct. Modular cable pinouts are not universal, even between different models from the same manufacturer. Use only a cable explicitly confirmed for your exact Enermax PSU model and revision. If you cannot verify that, use the original cable or replace the PSU. For a 6800 XT, a quality 750W or 850W unit with two dedicated PCIe leads is a safer long-term setup. Also, if you choose an NVIDIA card, check the specific model’s power connector rather than assuming every version uses the same cable.
The exact graphics card matters first. An RX 6800 XT generally uses two 8-pin PCIe power connectors, while some newer NVIDIA cards may use a newer high-power connector or an included adapter. For the 6800 XT, separate PCIe cables are preferable if your PSU supports them, but a daisy-chained cable is not automatically dangerous. If the power supply cannot handle the load, its protections should shut it down or the card may become unstable rather than the cable instantly damaging the hardware. That said, a 650W unit is close to the minimum for a 6800 XT, so replacing it with a quality modern 750W–850W PSU would be the more comfortable option.
I’m most likely getting the RX 6800 XT. Would it be reasonable to try it with the existing daisy-chain cable first and replace the PSU only if I encounter crashes or instability?