NZXT's Kraken series of prebuilt CPU water coolers has been around since early 2013 and when they were released, they took the All in One market by storm. Since then, the original X60 and X40 are still among some of the better solutions around but the competition has been fierce with new or updated units from Corsair, Silverstone, Antec, Thermaltake and many others. Now NZXT is launching the Kraken's next generation while consists of three new Asetek-supplied closed loop liquid coolers: the X31, X41 and X61.

In order to top of the performance abilities of their first attempts, NZXT went back to the drawing board. The result is a brand new waterblock and pump design that was handed down to Asetek for mass manufacturing. This update promises to be even more efficient at whisking away heat from even the hottest running of CPUs.

While absolute CPU cooling performance is first and foremost the primary task of NZXT's redesign, the pump plays a key role as well. In previous AiO designs fan speeds could be controlled so a user could have some control over their system's noise levels but the pump itself remained at a constant operating speed. This proved to be a bone of contention since achieving truly quiet acoustics proved to be a challenge with the pump chugging away. With the X41 and X61 NZXT is introducing a technology that's long since been available on custom water cooling setups: a variable speed pump which can scale its speed from 2400RPM to 3600RPM depending on load conditions.