Prior to installation, the CPU IHS and heatsink base were both cleaned with isopropyl alcohol before applying a small amount of the included Arctic Silver 5 thermal compound.
The Intel LGA775 mount for the Ultra-X uses an X-shaped metal backing plate with four brass studs. The backing plate must be installed before the motherboard is mounted into the case.
Once the backing plate is set into position with the four studs sticking up thru the socket area mounting holes, the big cooler can be carefully set into position and secured with four thumb screws. The cooler can be turned/positioned however best fits your particular motherboard layout. Due to its large size, the cooler may interfere with surrounding components on some motherboards but I had no trouble finding an orientation that worked perfectly.
The Ultra-X proved to be very easy to install. This particular motherboard can be a little challenging because of the NB and auxiliary heatsinks located around, and partially blocking three sides of the CPU socket area. It can sometimes be difficult getting your fingers in to tighten down the screws. However, I was able to accomplish the task while installing the Ultra-X with minimal frustration.
While I did not test the Ultra-X on an AMD platform, I suspect the included AMD mounting clip is not as robust as the Intel 775 mounting scheme. Using a single clip, which hooks onto a pair of lugs on the stock AMD retention frame, typically does not produce as much clamping force and does not hold a large heatsink as securely as the Intel 775 mount does.