vegetaleb So I inspected the strange humming sound like electric on my new PC system and it's obviously the brand new i5's fan!! Noise is in idle while the CPU is not warm (40c) , is this normal or should I ask for a replacement from pcandparts?
vegetaleb So it looks like I plugged the CPU fan into ''sys fan'' on the motherboard instead of CPU fan, I plugged it to cpu fan slot and the humming sound is much quieter, it's still there even at idle but not annoying, like if it was 6db and now 2db, sounds like the normal stock cpu fan now. I will perhaps put a thermaltake or cool master later when the choice will be broader