Typically computers with these larger memory amounts have fans that scream like a banshee trying to move impossible amounts of air over the memory and CPU. Getting something both cool and quite can be a bit difficult.
I had some 120x38mm fans from another server box that I pulled out because they were too loud and I didn't need the static pressure they were giving. They went in here. That 13mm (and the extra 1k rpm) moves so much more air.
The trick is to turn on the cooler's RGB in your 6000€ server to get a free speed boost. I am not liable for sysadmin's heart attack upon reading this.