I have no knowledge on this subject, but - According to wikipedia [0], fluorinert as used in the Cray was a single-phase coolant (no boiling). It needed fluid

I have no knowledge on this subject, but - According to wikipedia [0], fluorinert as used in the Cray was a single-phase coolant (no boiling). It needed fluid pumps and chilled water, at high energy cost; this phase-change solution avoids both. - Wikipedia claims fluorinert has a very long atmospheric lifetime and high global-warming potential. [1] 3M claims this new fluid is destroyed by sunlight [2], and doesn't have the same problems. [0] https://en.wikipedia.org/wiki/Cray-2#Packed_circuit_boards_and_new_design_ideas https://en.wikipedia.org/wiki/Cray-2#Packed_circuit_boards_a... [1] https://en.wikipedia.org/wiki/Fluorinert#Toxicity https://en.wikipedia.org/wiki/Fluorinert#Toxicity [2] (PDF) http://multimedia.3m.com/mws/mediawebserver?mwsId=66666UF6EVsSyXTtNxf2oxf_EVtQEVs6EVs6EVs6E666666--&fn=Novec649_6003926.pdf http://multimedia.3m.com/mws/mediawebserver?mwsId=66666UF6EV... (The "M.J. Molina" in the datasheet is the Nobelist and co-discoverer of the ozone hole)