should i go over 1.4v for 4GHz?
well, depend on chip quality.
some very lucky guys find good batch that can reach 4.0 ghz even at stock voltage
some have to set at 1.4 v in order to reach that clock..
some have to struggle with their voltage and have to set 1.5..
and others that unlucky enough even cant pass 3.2Ghz with their 1055T..
it's depend on chip quality and about the right setting.
that's why i ask you about cpu-z screenshoot..