What exactly is a power supply unit?

[Irene ❤]

It doesn't generate power. Our home socket supply that power. It's like a power converter to smaller pins.

Why are we paying hundreds to a converter? : x

The laptop's motherboard, graphics card, monitor all can work with just a small adaptor. powerful home appliances such as Air conditioner, water heater, fridge, light bulbs, vacuum cleaner don't require a PSU as well. Why the special need for it just for PC?

Hospitals overcharge for unnecessary scans. Car mechanics overcharge for unnecessary parts change. Maybe we've all been overcharged (pun) by the PSU all these years?

[_I_]

it was changed with atx 2.0 standard
around the pentium 4 era
thats when boards started using the 12v rail to convert power for the cpu
and intel spec required a separate 12v rail specifically for that so it has cleaner power without power spikes from hdd, and some gpus that had the molex power connector
classic pci slots are 3.3v and 5v, isa were 5v
pci-e uses 12v

[GigaCars]

a PSU is basically just so the computer can get the voltage it needs, also to keep the wires from exploding lol

extra power it generates can also give the computer time to clear it's cache to help keep itself from damaging itself in the event of power failure too

note: this is what i THINK it can do as well, i am definitely missing a LOT of facts, this is because i have barely any knowledge on what a PSU is for, but i do know it's a important part

[De Hollandse Ezel]

ok OP.

a computer powersupply needs not JUST to convert power from AC to DC.
it also needs to do so extremely stable while carrying up surges.

the normal grid of 230V 50hz.. in reality had fluctuations in voltage and hz it is not stable.. and that is even without factoring in a surge..

-> computerparts not want just 5v.. they want 5.00 volt..
(this means that for most travo's they deliver 5v which can be anything between 4.6v and 5.4v
which is fine for a soldering iron.. but not so much for pc parts that are made to operate within much more exact margins...
->
similair economics it is like why 99.999% pure alcohol costs 15000 euro per liter.. while 99% pure alcohol costs only 50 euro per liter.

there are plenty of Powersupply units that cost under 50 euro, VAT included.
but granded most midend and lowend systems will pick a psu somewhere between 80 and 150 euro.. still not "hundreds" but a sizable amount for "a transformator:"

this price difference comes due a few factors,..
-> the accuracy is a factor.. while even 50 euro computer psu's will meet the accuracy a pc needs.. there is no doubt that with a 500 euro psu you get much more stable and constant voltage.. much less fluctuation and that allows higher overclocking.. and less crashing

-> but another thing that drives the price up is "efficiency rating"
aka bronze, silver, gold, platinum, titanium"

efficiency has to do with powerdraw...
(while efficiency different when 0%, 25%, 50%, 75% or 100% of psu max amount is used..)
simplified :
bronze is always 80% efficient
silver always 85% efficient
gold 87%
platinum 89%
titanium 90%

it means that when your pc draws 500w of power... with a bronze rated psu you be drawing 625w from the wall.. while with a titanium rated you be drawing 555w from the wall.
-> this will mean lower utility bill but also less heat production.. as that inefficiency is lost as heat in the system.
**more efficient design uses more enginering and materials.. and thus cost more.
though you can today get a gold rated psu for about 80 euro.. so thats basicly the sweetspot pricewise...

----
than the max output... most of the cheaper psu's are rated only for lower wattages.. while the higher ones with 1000+w cost a bit more... hence why many midend use those 100-150 euro psu's.
logically making a transformator for 1200w will cost more materials to make than one for 600w driving up price.

----
than how WELL it is made.. better made psu's use heavier capacators.. that will be more resistant againt surges so even if lighting strikes your pc will n ot die.. while cheaper ones will have a lower limit for this.. and damage quicker.. likewise a psu made with more metal will dissepate heat easier.. and thus need less cooling...
finally a better made fan attached.. means it can cool with less rotations per minute.. a good fan can cost 30 euro.. a bad one 5 euro.. those extra costs does make your psu run much quiter.. which does not help performance.. but is a thing many are willing to pay that 20-30 euro extra for...

---
next we come to vanity.. generally psu's with modulair cables are prefered but also more costly.
for your pc permance it matters not which one you pick.. but it is easier to make your system look nice with modulair cables.. so call this vanity many pay 50 euro extra for.
logically making cables modulair (or even sleeved) costs more. to make for a manufacturer... as he needs to add all those connectors he would not have to add in a non modulair psu.|
(ofcourse people paying 100 euro for a set of cable replacements thats fully sleeved... thats vanity and overcharging like 30 euro phone charging cables do.. but well vanity has it's price...


-finally there is rating/connectors.. as powerdemands of parts change over time.. (gpu's mostly) you need other connectors on your psu.. often these new connectors are copyrighted by their inventor.. who charges a few dollar to those who want them.
(which drives up price but usually not by more than 10 euro per psu)

---------------------------
so 50 euro : basic psu, but it will lack a powerrating, be only 700w not be modulair... and not have decent surge protection and be quite loud.

150 euro.. proper psu.. platinum rating, 1200w, fully mnodulair, and decent surge protection and loudness.

80 euro.. somewhere in between as in for example.. 800w, modulair, but only gold rated and loud

the 500 euro ones generally have extra bells and whisles but not so much they are worth 3 times the 150 euro one..
**they go to insane high wattaghes of 1800w, they have titanium rating, they have settings that allow you to alter the power per rail, and such overclocking tweaks.. they are EVEN more stable.. for that 1% more overclocking potential.. , they have fabric covered cables in any colour you want... but while nice to have.. they are the sportcar of psu.. for most regulair drivers a "hundreds of euro psu" is not needed

one 80-150 euro.. will do fine for 99% of users.

[Bad 💀 Motha]

^ Most PSUs are generally quiet by design; IF you do not buy junk and that you buy one that well exceeds your needs for running everything under full loads. They can all generally be a bit audible if you buy a PSU that is too close to your full loads, which you should never be doing.

Most decent PSUs in USA are around $90-150 area, which is not outrageous at all by any means, again as long as you aren't buying junk. If you really need a 1200W or 1600W then of course you are going to pay a steep premium for those.

[Tonepoet]

Originally posted by De Hollandse Ezel:

efficiency has to do with powerdraw...
(while efficiency different when 0%, 25%, 50%, 75% or 100% of psu max amount is used..)
simplified :
bronze is always 80% efficient
silver always 85% efficient
gold 87%
platinum 89%
titanium 90%

This isn't completely acccurate. 80+ ratings only correspond to efficiency ratings at three different rated thresholds: 20%, 50% and 100%, except for titanium supplies

• White is 80% efficient across all three rated loads.
  
• Bronze has a curve of 82%/85%/82% respectively
  
• Silver is 85%/88%/85% respectively doesn't exist anymore for all practical intents and purposes. >_>
  
• Gold is 87%/90%/85% respectively
  
• Platinum is 90%/92%/89% respectively

Titanium adds a 10% load threshold, and has to be 90% efficient at 10% load, 92% efficient at 20% load, 94% efficient at 50% load and 90% efficient at 100% load.

To say that bronze is at least 80% efficient underrates it, and ignores the reason the ordinary white threshold exists. Summarizing gold, titanium and platinum by the lowest threshold they have to meet also underrates them, when they are typically expected to run more efficiently. Also ignoring the fact that 80+ ratings are only rated at specific thresholds implies that they have requirements outside of these threshods when they don't.

next we come to vanity.. generally psu's with modulair cables are prefered but also more costly

Modular power supplies aren't simply a matter of vanity. It's a bit easier to build if you don't have to deal with excess cable clutter, and less cable clutter can also help with air flow/space constraints. Moreover, if one of the power supply cables ends up being damaged you can, in theory, replace it (although this isn't necessarily advisable because getting a cable with the wrong pin-out can be disastrous).

These are practical considerations that make it so that you might elect to buy a modular power supply, even if you had a 100% opaque case, where nobody is going to see the tangled web of P.S.U. cables anyway.

R.G.B. lighting is pure vanity though.

finally there is rating/connectors.. as powerdemands of parts change over time.. (gpu's mostly) you need other connectors on your psu.. often these new connectors are copyrighted by their inventor.. who charges a few dollar to those who want them.
(which drives up price but usually not by more than 10 euro per psu)

Technically true, although it needs to be noted that the power supply connector standards age at a glacial pace.

[De Hollandse Ezel]

Originally posted by Tonepoet:

Originally posted by De Hollandse Ezel:

efficiency has to do with powerdraw...
(while efficiency different when 0%, 25%, 50%, 75% or 100% of psu max amount is used..)
simplified :
bronze is always 80% efficient
silver always 85% efficient
gold 87%
platinum 89%
titanium 90%

This isn't completely acccurate. 80+ ratings only correspond to efficiency ratings at three different rated thresholds: 20%, 50% and 100%, except for titanium supplies

• White is 80% efficient across all three rated loads.
  
• Bronze has a curve of 82%/85%/82% respectively
  
• Silver is 85%/88%/85% respectively doesn't exist anymore for all practical intents and purposes. >_>
  
• Gold is 87%/90%/85% respectively
  
• Platinum is 90%/92%/89% respectively

Titanium adds a 10% load threshold, and has to be 90% efficient at 10% load, 92% efficient at 20% load, 94% efficient at 50% load and 90% efficient at 100% load.

To say that bronze is at least 80% efficient underrates it, and ignores the reason the ordinary white threshold exists. Summarizing gold, titanium and platinum by the lowest threshold they have to meet also underrates them, when they are typically expected to run more efficiently. Also ignoring the fact that 80+ ratings are only rated at specific thresholds implies that they have requirements outside of these threshods when they don't.

next we come to vanity.. generally psu's with modulair cables are prefered but also more costly

Modular power supplies aren't simply a matter of vanity. It's a bit easier to build if you don't have to deal with excess cable clutter, and less cable clutter can also help with air flow/space constraints. Moreover, if one of the power supply cables ends up being damaged you can, in theory, replace it (although this isn't necessarily advisable because getting a cable with the wrong pin-out can be disastrous).

These are practical considerations that make it so that you might elect to buy a modular power supply, even if you had a 100% opaque case, where nobody is going to see the tangled web of P.S.U. cables anyway.

R.G.B. lighting is pure vanity though.

finally there is rating/connectors.. as powerdemands of parts change over time.. (gpu's mostly) you need other connectors on your psu.. often these new connectors are copyrighted by their inventor.. who charges a few dollar to those who want them.
(which drives up price but usually not by more than 10 euro per psu)

Technically true, although it needs to be noted that the power supply connector standards age at a glacial pace.

I did state in my post they will have different efficiency at different loads.
and I kept it simplified for OP,

the essence of my simplefied version did still apply..
that the efficiency gain from gold to titanium.. is marginal... and most the gain is between bronze and gold... (and that have NO ratting today not even bronze.... well like silver rated psu's I have not seen any of those sold in quite a while)

and as for the in between values... I'd be surprised if it not followed a curve... like if a gold psu at 72% load would suddenly only have 50% efficiency.. that be quite odd.. so I always presume the efficiency is somewhere between the rated value above and below.

....
as for cable replacement.. for modulair devices... do you know anybody who ever has done that?
***few brands sell their cables seperate from their psu.. those that do only sell full replacement kits.. so for ALL cables not the one.. at a pricepoint you might as well get a brand new psu. and to go offbrand.. well no guarantees what that going to do with efficiency, safety etc etc can't know if that cable is produced upto specs..
(same as why I buy those overpriced 30 euro branded phone charging cables and not a 2 euro imported one from alibaba)