I accidentally bought the RM850e power supply, not realizing it doesn't come with enough cables for my RTX 3080. The RM850e has three PCIe slots, but one is used for the CPU. I'm wondering if it's possible to power all three connectors on the 3080 using only two PCIe cables. Does anyone know if there's a cable that allows me to do this, or could I run a 3x8 pin to 12V cable through the PSU's 12V slot? I've mostly found single PCIe cables or 12V to PCIe options online, but I'm not sure what's safe or effective.
4 Answers
Using cables that didn't come with your PSU can be risky, so be careful. Ideally, you should use three separate cables for safety. If you were to use a pigtail adapter, remember that those cables are rated for around 270 watts, with a safe draw of about 150 watts per cable. Since your RTX 3080 can hit up to 320 watts, using a pigtail could push it beyond safe limits, which might lead to problems over time.
It's a bit tricky with the RM850e due to its limited PCIe connections. While Corsair provides some clarity on their cables, you should definitely stick to cables that come with your PSU. You might want to check if your PSU has a 12V-2x6 to 2x6+2 cable, which could work, giving you three 6+2 PCIe connections, with two ports left for the CPU. Just make sure that mixing cables doesn't become an issue due to power limits.
Does your PSU not come with both an 8-pin connector and a pigtail 8+8 connector? It's not catastrophic if one 8-pin can't go directly to the 3080 for all connections, especially if you're just using stock settings.
What CPU are you using? You might not need to connect both CPU cables for your setup. It could free up some connections for your GPU.
Related Questions
Lenovo Thinkpad Stuck In Update Loop Install FilterDriverU2_Reload