After testing the Zalman FX100, one thing seems to be clear to us: there is no fanless cooler capable of cooling a high-end CPU, especially if it is overclocked. Even with all its size, the FX100 showed a barely reasonable cooling performance with a noisy fan installed.
Mounted with no fan, the FX100 didn’t handle our CPU, even considering it has a very light overclocking and that there was a case exhaust fan at the rear panel, very close to the cooler. The CPU reached the temperature limit and throttled down the clock. Maybe it can cool a low-TDP processor, but it seems pointless to install such a huge cooler if even the stock cooler cools the CPU better, with a very low noise level.
The Zalman FX100 was a complete disappointment. It may have a stunning look, but the installation system and the cooling performance have much to be improved.