Summary: The most significant feature of the ZM850-HP Plus is, without any doubt, its cooling system that utilizes a dual heatpipe heatsink for silent operation. Indeed even with over 50°C ambient and at full load the cooling fan worked silently enough, at least for my ears. Despite being specified officially to 40°C operation, over-temperature protection did not trigger during our 50°C+ testing, which that means that the secondary heatsink's temperature was not getting too high.
Pros: Dual heatpipe cooling system for silent operation, High efficiency throughout 20-100% load, Tight voltage regulation at +12V and under 3% for 5V, Excellent +12V performance in Advanced Transient Response tests, Very good ripple/noise suppression at +12V and 3.3V, Supports up to three hi-end graphics cards
Cons: High price, 3.3V outside ATX spec during 2nd Advanced Transient Response test, 210 mm long, might not fight all cases, Mediocre efficiency at, Lacks a second EPS connector, Power distribution not optimal