Have paged through the manual and done a quick search, but my Google-fu is failing me - can't find anything on voltage read points for the X99 Deluxe (if any). It could be that CPU-Z is simply getting confused (can happen with new gen) and software readings are either wrong or being misinterpreted; ideally you'd check with a DMM but with no obvious read points I'm not sure how to go about doing that.