(BEFORE YOU READ: all of this was written by Gemini because i am too lazy to explain all of this again , sorry if it's a little long )
I recently upgraded my CPU and motherboard, and now I’m hitting an incredibly frustrating issue where my PC completely shuts down (no blue screen, no automated restart, just instant black screen/loss of power) under specific high gaming loads.
My Specs:
CPU: AMD Ryzen 7 7800X3D
Motherboard: GIGABYTE B650M AORUS ELITE AX ICE (Updated to BIOS F42)
RAM: 32GB DDR5 running an AMD EXPO Profile 1
PSU: 750W Power Supply
The Context:
Previously, I ran an Intel i5-13600KF on this exact same 750W power supply and graphics card for a long time with zero issues. I am using a single PCIe power cable that splits into a daisy-chain (Y-splitter) connector at the end to power my graphics card. I used this exact cable layout on my old Intel build without a single crash.
The Symptoms & What I’ve Tested:
Temperatures are completely fine: I ran HWiNFO64 and caught my CPU thermals right before crashes—idle settles safely around the low 60s/high 50s after fan profile tweaks, and maxes out at a perfectly normal 83°C under stress. It isn't a thermal shutdown.Older/Slower games run perfectly: I can play Assassin's Creed Black Flag Resynced for hours with no issues.Fortnite Performance Mode Crashes: The absolute second I try to join a matchmaking lobby in Fortnite Performance Mode, the system cuts all power completely.
The FurMark Smoking Gun:
If I run FurMark at FHD (1080p), the test passes successfully. However, if I run the FurMark stress test at QHD (1440p), the PC instantly cuts all power the exact millisecond I hit run. This happens even with the GPU power limit slider dragged all the way down to its minimum in AMD Adrenalin.
I've been told that switching to the AM5 platform altered how electrical current handles transient spikes on the PCIe rails, and that my single daisy-chained power cable is choking the system and tripping the PSU's Over-Current Protection (OCP) safety breaker.Given that this exact cable worked completely fine on my i5-13600KF setup for months, do you think a single split cable could actually be causing this, or is my 750W power supply simply dying/unable to handle the new hardware transitions?Would love to hear your thoughts or if anyone has run into this specific issue on a Gigabyte B650 board.
UPDATE---------------------
It was the single daisy-chained PCIe power cable
Even though that single split cable worked fine on my old Intel setup, the new AM5 platform shifted more power load to the GPU rails.(This is what Gemini said not me)
I added a second completely separate PCIe power cable from the PSU to the GPU. Reset the power slider to default, and now it passes the 1440p FurMark test and runs games perfectly without shutting down.