"The Spire Fourier IV SP607B3-C is a heavy heatsink, so it installs with very secure mounting hardware that is quite inconvenient. The heatsink is compatible with socket 754/939/940/AM2 AMD Athlon64 processors and socket 775 Intel CPUs. In each case, the motherboard must be removed from the computer case and a metal rear-PCB support bracket installed. The Fourier IV's mounting screws go in from the back of the motherboard to the front where the heatsink support bracket is. It takes at least two hands to do this, and the rear metal support plate doesn't have an adhesive patch to keep it in place so it's tricky."