Rexper

Could we stop relying on that tier list so much... Remember, that list is subjective. Do you understand why those power supplies are "unsafe" or good? If you read professional reviews, you would. EVGA 450 B3 review at Tomshardware. The biggest flaw of the power supply is the non-functioning protections. Overloading the EVGA b3 will not only kill it, but can harm your system components and can be dangerous.

No.

If you’re using a semi-fanlwss mode, where the fan isn’t spinning, it is advised to face the fan grill upwards for the hot air to naturally rise out.

Pre-2015ish the m12ii/s12ii used the Adda AD1212MB-A70GL, a ball bearing fan. The units got a rework in ~2015, with internal differences being the fan - Hong Hua HA1225M12F-Z with an "FDB" - aswell as the primary mosfets and secondary SBRs. The two APFC MOSFETs and two main switchers were changed from FDP18N50 (10.8A @ 100°C, 0.265 Ohm, 500V) to 5R250P (9A @ 100°C, 0.25 Ohm, 550V). Not exactly sure about the secondary rectifiers, but the newer revision includes a PFR30L50CT (I'd say for the 5V) whereas the older one used a SBR40U45CT. Nevertheless, the M12ii 520 is group regulated and uses a crappy protection IC. My vote's for the Pure Power 10.

... Bugs.

Well, assuming 0.032 and 0.027 Ohm ESR, both the SC and EG have a calculated (by me) lifespan of ~110 - 130 thousand hours. At 60C the Chinsan supposedly lasts 8 thousand hours longer Or I just get my calculator flawless before commenting...

Where’d you find those ESR values? For the Teapo SC all I could find was it’s impedance = 0.0028 Ohms. I’d imagine ESR to be lower?

Some say a 600w is preferable for OC 1080TI or Vega due to their large transient spikes (50A+ IIRC).

Atleast with the case of the Asus 970 Strix incompatibility it was an issue with ripple.

You can find the be Quiet Pure Power 500, Corsair CX550 and CX550M, Corsair Vengeance for that price. https://geizhals.de/?cat=gehps&bpmax=62&v=e&hloc=de&filter=aktualisieren&sort=t&xf=1119_2~360_500#productlist

Here is the issue with these sorts of forums... Some people research for 2 minutes, and believe they know the topic inside out. So they go to make stupid recommendations, and ignore those trying to help... You obviously have no idea how a power supply works... Why bother recommending something you don't understand? When you know there are others whom have years-worth of knowledge on power supply that can comment. PSUs 101: A Detailed Look Into Power Supplies Personally I like to stay clear of unbranded/ low-names in power supplies, as they are more likely to use fake ratings/labels or bait-and-switch. Read professional reviews.

650W?... 750W?!! We're talking about an i5 + 1080ti, now... A good 550W will be fine. The EVGA 1300 G2 is loud. That's about all that's wrong for your system. Your could sell it for 200 ? Not for resail price, because they'll only be getting three years warranty. You can find a high quality 550W power supply for ~£80, such as the Corsair RMx, Bitfenix Whisper.

Cap brands alone won't say much. Capcitor lifespan depends on many factors including it's size, voltage, capacitance, ESR, ripple current, etc, and most importantly it's environment. Here are technical notes by Rubycon relating to electrolytic lifespan. That said, I'm not suggesting these capacitors will last very long. Also, there are so many more aspects in a power supply that can define its quality. It's a pretty good budget option. Double forward + DC-DC with a full set of protections and a full EMI. The capacitor and fan quality isn't any more I'd expect from such a low-price power supply.

For OPs case - 300W 24/7 for 10 years x12 computers - they'd be saving almost fifteen thousand kilowatts from using titanium power supplies as apposed to gold. So even if a titanium costs $60 more you'll be saving money after half a decade or less.

"But single rail PSUs don't need OCP!!!1! And those other protections weren't around when S12ii was built". Seriously, no 12V UVP or OCP on a group regulated power supply is not something desired. You'd rather advise from people not thinking at all? There are other forums for that.. I can only wish you luck

Tomshardware: How We Test Power Supply Units

Why don't we compare components in real power supplies. Like the Seasonic Focus Plus 750 and the Seasonic Focus Plus 850. The only internal differences in this case are the main switchers, APFC mosfets, and the bulk capacitor (capacitance mainly). The bulk capacitor because higher load = shorter hold up. Fan speed, efficiency, and cabling would of course differ. The Corsair RM650X and Corsair RM550X in another example. The 650W is missing a relay for the thermistor. The main switchers, APFC mosfet and boost diode, and bulk capacitor are changed. For a third example let's compare the EVGA 450 B3 and EVGA 650 B3. The 450 includes a TVS diode in the transient filter stage (I couldn't find the TVS diode on the 450, could someone point it out?). The 650's bridge rectifier can support higher current. The 650 has different APFC mosfets and also two instead of one. The 650 has more capacitance in the hold-up (bulk) capacitor. The main switchers in the 650 can support twice the current than the 450 B3. The 650 also includes an additional APFC controller. And lastly the 650 has double the amount of 12V MOSFETs. Primarily the mosfets and bulk capacitor are upgraded to support higher currents. The fan model and secondary caps are also seen to change sometimes.

Better in reviews. But reviews aren't always accurate to real life scenarios. For example, some graphics cards can cause high ripple on the power supply. This was the case with the Seasonic Focus Plus and Asus 970 Strix, so they're replacing the cables with inline caps to improve ripple.

Considering the EVGA B3 550 uses a 390uF cap and measured 16.9ms at AC loss to PWR OK end, I wouldn't say it's impossible. https://www.computerbase.de/2018-08/be-quiet-s9-evga-b3-80plus-bronze-test/3/#abschnitt_stuetzzeit__erp What else can affect hold up time, besides primary topology and bulk capacitor size? I've found data for atleast a dozen PSUs of the same primary topology, but can't find really find a trend. For example, we have the EVGA BQ 850 with 960uF that only measured 12.42ms. Whereas there's a Cougar LX 600 with 330uF measuring 12.9ms.

The 550 Focus Plus has issues with Vega GPUs. The newer 650 Focus Plus models (serial number R1712AA1B156**** and newer) have resolved this. This can be seen from Seasonic's comment here: https://gathering.tweakers.net/forum/list_messages/1801761/last

The 550 Focus Plus has issues with Vega GPUs. The newer 650 Focus Plus models (serial number R1712AA1B156**** and newer) have resolved this. This can be seen from Seasonic's comment here: https://gathering.tweakers.net/forum/list_messages/1801761/last

Real life for only your scenario, which could be one in a thousand. Because in real life scenario there are too many factors for an opinion to mean anything, unless you describe those factors. This could include workload, case, other parts, how sensitive you are, how far away the computer is, what/if headphones are on, environmental noise, and what you define quiet as. Whereas “reviews” or testing will describe the RPM or noise levels with a set methodology so the readers can decide for themselves. For you it may be “quiet”, for many other people it may be “loud”.

Don’t worry about that “peak efficiency”. Because the “peak” is different for every PSU - for some it’s at 30%, some 50%, some 70%. And the efficiency difference between those loads (~30% - 70%) will be very small. And every PSU will be more or less efficient, because they’re built differently. For example, a 400w be Quiet! Pure Power 10 at any load may be more efficient than that FSP 650 at its ‘peak’, simply because it’s an overall more efficient PSU. So don’t waste time doubling your required wattage. Just choose a quality PSU that can support your build. And S12ii power supplies are still group regulated, along with missing protections. You want to look for a DC-DC PSU.

Because that's all you need and you get no benefits at all from a higher wattage power supply? You only lose money and possibly end up with a noisier PSU. Don't worry about efficiency curves. When you factor in the efficiency of every load the computer will be in (eg. idle, gaming) the power saved on a 550w compared to an 850w PSU, assuming they are from the same series and platform, are negligible. If you want efficiency, choose a PSU that is overall more efficient. Don't waste your time messing around with wattage capacity. For OP's system, 450w is more than enough. If they plan to upgrade to a top tier graphics card like a GTX 1080ti 550w will be suitable.

Also, higher wattage power supplies are generally less efficient at idle loads. So the real world difference in the power bill would be even less noticeable.