I just installed a 7900XTX in my system, powered by a be quiet! Straight Power 11 850W Platinum PSU, which I was told should be sufficient. The card has three 8-pin PCIe slots, and I'm currently using a Y cable from PCIe 1 on the PSU that splits into two 8-pin connectors. I also have a single 8-pin going from PCIe 3 to the last slot on the GPU. According to my PSU manual, PCIe 1 corresponds to rail 3, PCIe 2 is split between rails 3 and 4, and PCIe 3 is rail 4. This configuration means I'm drawing about two-thirds of the power from one rail and one-third from the other.
I've run benchmarks both overclocked and at stock settings without tripping anything, but recently my PC shut off completely, and I could only restart it by cycling the PSU manually. I'm looking for tips on how to resolve this issue. My plan is to purchase another 8-pin PCIe cable to distribute the load evenly across the two rails by connecting to PCIe 2, instead of using one of the Y cables. Based on what I've read, I should be able to multi-rail the 7900XTX with 850W without triggering the overcurrent protection.
1 Answer
It sounds like your PSU should be fine, but it's possible that it’s getting triggered by the spikes from the 7900XTX, which can go over 500W for short bursts. Make sure you have the right cables, though! If you're buying new ones, ensure they are compatible with your PSU since modular cables can vary in design.
I’ve only got the Y cable right now, which has two 8-pin ends and one single 8-pin cable. I'm considering getting another one from be quiet and connecting it to PCIe 2 to balance the load.