The new Assassin IV cooler achieves high performance but doesn’t exceed the performance of the previous model, which I find weird. Usually, when a new cooler comes out, you expect it to provide even a slight performance increase over its predecessor, but clearly, this is not the case here. So I can’t help but wonder why someone should prefer the new Assassin over the old one. The first and most important reason is that the previous model is no longer available. If you find it somewhere available and at a good price, you should not hesitate to acquire it. The Assassin IV has an interesting exterior design, which will probably divide user opinions on whether it is appealing, and the black color scheme manages to hide, to a degree, the vast dimensions. Another asset of this huge cooler is that, thanks to the rear-mounted fan, it provides excellent RAM compatibility, while it also retains high compatibility with the mainboard VRM’s heatsinks.
Similar to the be quiet! Dark Rock Pro 5 and Dark Rock Elite coolers that I recently evaluated, the Assassin IV has an embedded PWM controller with two levels, low and mid, which I don’t find necessary from the moment its fans are PWM controlled. The capability to easily mount a third fan looks interesting, although if you do that, you will destroy the cooler’s box design. The build quality is high, equal to the other high-end coolers in this category, and mounting is relatively easy if you do it with the mainboard outside the chassis. This is a high-end cooler with an interesting design, which cannot beat the aged Noctua NH-D15 in performance. This is why Noctua didn’t bother so far to release an NH-D16 because from the moment the existing product leads in performance, there is no point in replacing it. Only when the competition offers something notably better, I suspect Noctua will do that.