- If I booted into Safe Mode with Networking it would remain stable and not reboot.
- If I connected the system to a basic Linksys 10/100 router it would be stable.
- If I disconnected the LAN cable from the gigabit router or disabled the internal NIC it would be stable.
I pulled another Corsair CX430 from inventory, tried it, and got the same rebooting behavior.
During a long chat session with Intel support it occurred to me to install Intel’s Desktop Utility that measures fan speed and voltages. IDU immediately began warning me that the +3.3V supply was too low (3.080V). We decided it must be the NIC circuitry (after trying several different NIC driver versions) and assumed that the Corsair CX4320 PSU must be incompatible with the DQ67SW, or at least the +3.3V supply is marginal.