"When I first received the new components for the Opteron workstation I wrote about in December, one of the things I knew I wanted to do was to reinstate my water cooling setup that I had on my Xeon system. The problem with this was that the Xeon blocks I had would not work on the Opterons, and that the 1/4” ID (inner diameter) tubing was not compatible with most modern water blocks. It seemed to me that it was time for a complete redesign of the cooling system. For this I turned to one of the leaders in the water cooling field, Danger Den. These guys had all of the components I had been looking for. This included their high-performance water blocks and other components made by other manufacturers. I'll walk you through what I did to go from an air cooled to a water cooled setup, which parts I chose, and why I chose them."
Source :
LinuxHardware.org