At first I thought it did.
I’ connected the new GPU using a cable that came with my PSU but hadn’t been used before installing the 1660 Super. Whilst testing the theory that the cable or the PCIe / Peripheral inputs on the PSU unit itself might be faulty, I noticed that the little clip on the 6+2pin PCIe cable that hold the additional 2pins in place, was bent. Meaning that the large clip on top of the cable, that clips onto the GPU, could clip into place without the 6pin section being fully inserted.
Normally I would notice the cable not being fully inserted as I usually check for a gap between the cable and the socket on the GPU by trying to run my finger nail between the two (which is why I noticed the cable wasn’t fully inserted this time).
I made sure to fully insert the cable and then I performed some stress tests with FurMark… probably an hours worth in all, between using the system normally whilst diagnosing my now dead firewall appliance.
The system performed normally for two days, which lead me to conclude that even though it would have meant inserting the cable with the bent clip, and the old reliable cable, wrong around 10 times or so, it would seam to indicate that it was user error.
Only that’s all out of the window again as the system has started power cycling today. So I tested my PSU with my ThermalTake Dr Power II and all the voltages and the PGS are within spec. I’ve now removed the card, plugged my display cables back into my old GPU and everything is back to normal (touch wood) and to the hardware configuration that I’ve never had any issues with.
If it’s not the GPU, then I’ve got no idea what else I can feasibly test.