UEFI installation is primarily needed for two things. The first is getting TRIM to work under RAID using the original, unmodified ASUS UEFI BIOS (i.e. without a patched OROM) as BIOS version 3404 on the Rampage IV series has the Intel UEFI driver. The second reason is speeding up Windows boot as only with a UEFI installation you can completely disable CSM (compatibility support module).
Here we detail exactly how to setup your Rampage IV motherboard a new install of Windows 7 or 8 OS in UEFI mode.
