Introduction In the forum, we often get asked – “what is the best water cooling block?” – but we seldom get asked about the radiator. For as much attention and dedication as water blocks have been given throughout the years, the radiator (heat exchanger) has sat as a dark horse and unheralded system component. Yet, of course, it is a necessary part of the whole cooling system. Luckily times have changed. In the last few years we’ve seen some glamorous high quality build radiators surface on the market. Watercool has a well-earned reputation for manufacturing top notch water cooling products for enthusiasts. The Heatkiller water block series provide one of the best water blocks available from the German water cooling pioneer. Today we are going to focus more on their HTSF2 heat exchanger to see how it compares to their excellent water block series. The HTSF2 stands for Heat-Transformer and the number 2 represents version two. Watercool offers two flavors for the HTSF2 series; the LT and LTX. These are available in single (120mm), dual (240mm) triple (360mm), and even in quad (480mm) size. We have the HTSF2 3×120 LT in our water-cooling lab and we’re ready to put it through some rigorous tests to see if its performance is as good as its glamorous aesthetics. Read on to find out more.