Don't get me wrong. The cooler works in a 2U form factor server. The problem with the cooler is the fan. The fan whistles at around 5000 rpm. BUT, if you put your hand on the other side of the radiator, you won't feel much air. I don't know where they get 28cfm from, but it's not at 5000rpm. I ordered another fan, Noctua, for this radiator. For the total price I could have gotten a much better cooler. So keep that in mind when purchasing.
This is a good CPU cooler for servers and high-performance workstations. I tested it on an Hp workstation and the fan was not noisy, not as noisy as the Dynatron CPU cooler fan. This CPU cooler is top notch. The next test of this CPU cooler takes place on an Asus mainboard. Update 07/05/2018 I installed a Silverstone CPU cooler on an Asus motherboard and it provides a higher CPU temperature than the stock Intel CPU cooler I installed and it is very quiet and was very easy to install .
I recommend this cooler if you don't mind buying a quieter 60mm Noctua fan for it. Pros: 2U β Solid build quality. within safe temperatures. (operates 24/7 as a cloud computing node on the "bare metalβ). Noctua, and now it works silently, but at the same time stays within safe limits.