OK Resolved. I want to share my experience, and if you are having a ram code or a no video issue this might and probably be useful:
I revived this thread only to share my "research".
I gave up and bought an p8z77 pro, and the issue went away.
2 weeks ago, my father had his ROG laptop stolen, so he asked me to build him a desktop and this is what I ordered for him :
i5 3570k
Thermalright Silver Arrow SB-E Extreme
16gb gskill ripjaws 2400
maximus v formula
gtx titan supercocked
etc..
When everything arrived and started building it i noticed they sent us the wrong board, got one for amd processors.
Instead of sending it back, I went and tried the dreaded maximus v extreme with the gskill ram, and perfect no more code 20. Just for laughs I tried my corsair vengeance and the code 20 came back... So it definitively was a ram incompatibility issue.
I read a lot of complaints of rog boards with ram codes using corsair vengeance, and also read that this ram is better suited for amd applications, so at least in my case and probably in others my rog board is not compatible with this ram, even with the latest bios.
I aslo came across another issue which didnt turn into such a nightmare. Since the silver arrow when mounted vertically takes the space of the native 1st pcie slot, i installed my card on the 2nd slot. The motherboard started detecting the gpui as the main card even if the maximus v extreme doest have a vga port and had no video with no error code. It just booted into windows with a black screen. This was a 50/50 thing. So i ended up rotating the silver arrow horizontally, removed one of the removable ram fins and installed the titan in the native pcie slot. Issue solved...