First boot on ICE:
After the first boot, it’s important to check the temperatures in your bios. This way, you’re absolutely sure the tube is mounted correctly and the thermal paste is applied correctly.
In my case the recorded -37°C temperature is not that great, but the next day I found out that I was most likely a BIOS issue, don’t trust the onboard temp resistor. Swapping the SLI-D DFI motherboard for an Ultra-D sample made the temperature drop to -50°C in the BIOS read out.
At these subzero temperatures the exposed parts of the copper tube started to frost:
When the tube was cooling down, frost started to form at the base of the tube.
It’s not quite easy to make sure everything remains “ice free” on the outside, but some toilet paper wrapped around the exposed section helped diminish the frosting and the risk of condensation leaking onto the motherboard.