so voltage on air is not always an important sign , my 6280mhz 01 chip was 4c8t 1.385 only for xp... but not bad with ln2... and i had an 6200 chip for 3Ds and 6050 for 06 that could not boot even 4.8 below 1.4v on air. and some 5ghz 1.41v that can not pass 06 @ 5700