ATX standards means +3.3 V, +5 V and +12 V?
Yes, this is the ATX PSU standard. Namely; safe voltage ranges are:
+12V DC rail - tolerance ±5% ; +11.40V to +12.60V
+5V DC rail - tolerance ±5% ; +4.75V to +5.25V
+3.3V DC rail - tolerance ±5% ; +3.14V to +3.47V
-12V DC rail - tolerance ±10% ; -10.80V to -13.20V
+5V SB rail - tolerance ±5% ; +4.75V to +5.25V
ATX PSU standard tolerances are actually pretty wide and it would take exceptionally bad PSU, not to meet the ATX PSU standard. Still, PSU age does increase the rail tolerance and if brand new PSU barely meets the ATX PSU standard, it soon won't meet it. Hence why to get as tight tolerance PSU as possible, among other things.
Also, was the rail testing done with only PSU? Or was there any meaningful load put on the PSU? Since when the load is on PSU, it really shows it's true colors.
In a similar example: just because you start car engine, doesn't mean car drives fine. And you can not assume the car drives fine, just because you got the engine started.
I actually watched some testing of this PSU before buying it
Care to link the reviews/videos you watched?
Anyone can take olliscope and hook the PSU on it, make some tests and call the PSU good. That doesn't mean the PSU is actually good. What it takes, is reputable reviewer, e.g our own in-house PSU reviewer: Aris Mpitziopoulos who has written PSU reviews for Tom's Hardware and who is also founder of Cybenetics (
https://www.cybenetics.com/), which puts PSUs through far more in-depth testing than ATX PSU standard specifies.
Or Jon Gerow (aka jonnyguru), who is the de facto guy when it comes to PSUs. jonnyguru has reviewed loads of PSUs in his years and he is currently working at Corsair as director of PSU engineering.
Other reputable PSU reviewers include, but are not limited to, are: Steve Burke (GamersNexus), Hardware Secrets, PC Perspective, [H]ard OCP, AnandTech, KitGuru, Tech Power Up.
So, when it comes to PSU, it must have:
* official specs site
* review by reputable reviewer (preferably several reviews by several reputable reviewers)
Good to haves are:
* cybenetics report
* long warranty
* high efficiency
* good standing in PSU Tier list (
https://forums.tomshardware.com/thr...er-list-rev-14-8-final-update-jul-21.3624094/)
* good PSU brand reputation
* good PSU OEM (the one who made the PSU)
As for other safety stuff, this PSU has all the OPP, OVP, etc protections and a 5 year warranty.
There are 6 protections modern day PSUs have.
Your PSU has: OPP, OVP, OCP, SCP
specs:
https://seasonic.com/b12-bc#specification
My PSU has: OPP, OVP, UVP, OCP, OTP, SCP
specs:
https://seasonic.com/prime-titanium#specification
So, your PSU is missing UVP (Under Voltage Protection) and OTP (Over Temperature Protection). Here, you can not say that your PSU has "all" the safety stuff.
Oh, and your unit has 5 years of warranty, while my unit has 12 years of warranty.
At current date and time, anything less than 7 years of warranty isn't considered good. While 10 years of warranty is preferred. And 12 years of warranty is ideal.
Like i said before, your PSU isn't bad. It's mediocre. But since PCs are sensitive electronics, average power supply can cause issues.