I believe VR IN is the voltage detector in your VCore VRM, while the normal 12V detects right at the plug. So basically, it's 12V with some voltage drops. No it doesn't have to comply with 5% requirements. But, 11.4V @12V is dangerous, especially if you have a high end system and an old-designed PSU.
That Chieftec PSU was decent, when it came out back in 2010 or something. Now the design is just plain outdated and should not power anything beyond a GT 1030 and a quad core. Also don't just "get a seasonic". The S12II isn't that much different from the Chieftec, and you might miss better units that are actually cheaper. If you would like my recommendation, where are you from and what's your favourite online store for reference?
Thanks for the reply.
I'm on 9700k (having problems overcloking it to 4.9GHz because of the heat, having Noctua NH-D15S. But I will create separate post for it). My Chieftec is probably from those days. I only replaced cooler there with Noctua high pressure fan.
I did have problems with my Aorus Elite Z390 where it couldn't POST with the stuck CPU led. Shipped to service center twice! Service center couldn't identify the problem. Later it just started working. (Now wish I'd had Pro WIFI version actually, but the Elite has all the minimum needed.)
I tried with Aorus Pro Wifi while mine was in service. That wouldn't boot either now with RAM led on. POSTed fine after I removed CMOS battery for a few minutes.
So maybe those were the PSU tricks actually. But now it works stable again.
But to the point of the question.
Currently I'm looking at 650W
https://seasonic.com/focus-plus-gold
Thought on getting fanless one
https://seasonic.com/prime-fanless-px but it's very expensive.
However I saw some posts complaining about coil whines - such would be unacceptable as silence to me is crucial.