volt edit from bios not work

[drrobert]

i Tried to edit my bios with this setting:

http://imgur.com/a/YFfgV

with gpu 1145mhz 900mv / 1191 950mv and i use 1190 for gpu mining, on window on zcpu it will show 1volt for gpu instead 900mv, funny thing claymore on startup use right voltage after dag creation switch to 1volt again, wattman if i try to override after 10 sec it will go back something like it lock it. i tried also on claymore voltage regulator but it don't edit setting (i'm on window i know not working on linux)

nitro+ 480 4gb