I had serious video corruption/artifacting issues with my 20" G4. Be sure to read my 20" thread entirely before starting. I never got the Haswell NUC to work properly, ended up having to revert back to an HD4000 based NUC. Not the planned solution, but it worked. That Haswell NUC is now performing flawlessly in my A1076 iMac G5. Cheers.