rever5e :
mr1hm :
try using Vdroop Control, i edited my post earlier, you may have missed it
Sad but it seems like there's no vdroop control option on this mobo too.
EDIT: that's for the G45, jsut noticed you had G43, let me see what i can find
EDIT 2:
http://www.madshrimps.be/articles/article/1000344/MSI-Z77A-G43-Socket-1155-Motherboard-Review/2#axzz2g7iO1Toi - just start from the 4th page ("Testing Methodology and Results") if it doesn't take you there automatically.
- the link shows the board is indeed lacking many voltage controls for the CPU in the BIOS, not to mention, the fact that it's completely missing voltage options from the CPU's IMC (VCCSA/System Agent Voltage).
if it were me, id probably result to using OC Genie II if im having a hard time stabilizing small overclocks like 4.2-4.3GHz . id probably make sure to test it first though and see if it helps in raising and lowering CPU Voltages correctly since your manual overclock right now for some odd reason drops CPU voltage when under load.
if OC Genie II correctly raises (while under load) and lowers (while idling) cpu voltage, i'd probably try an use the settings that OC Genie uses and try to optimize it a little further. simply put, i just don't think there is much you can do due to the lack of CPU voltage controls.
is this a new PC setup for you? if you didn't get the mobo/3570k recently, how long have you had it? if you want to still overclock, i would highly recommend you upgrade that motherboard as it'll cause nothing but headaches later.
- something along the lines of a Gigabyte Z77X-UD3H (you could look @ some motherboards that are slightly cheaper around the $125-$150 range as well), will most definitely allow you to overclock higher with lower CPU voltage as well as have CPU/IMC voltage controls.