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?

[Spanky]

it's not a converter.

Power is put into the capacitors switched from active to direct and pulled slowly through regulation.

[Spanky]

Irene ❤님이 먼저 게시:

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

Air conditioner, hot bath, fridge, light bulbs, vacuum cleaner, even laptops - powerful home appliances all don't require that big square junk. Why the special need for that extra converter?

because if you connected directly to a power line it would be a lightening blot of fun.

[Bad 💀 Motha]

Before I just bust out laughing at another persons just... total lack of education, I'll just speak using these instead.

https://www.youtube.com/watch?v=i9ZnaA8DZDs

https://www.youtube.com/watch?v=YCQhGE176Bg

FYI, it's a real shame you kids have not learned anything in schools in the last 20-30 years because when I was in school, we actually learned all of this and that was back in the 80s and 90s.

[MonkehMaster]

I suggest reading up on PC power supplies and how a homes electric works and why it's known as "dirty power", along with maybe appliances and their differences from a PC and other sensitive electronics.

a PC is nothing like an appliance and a PC requires clean balanced power, without fluctuations, an appliance is a ton more forgiving with what I mentioned and said power.

I will also suggest and it should be common place, to use a UPS to protect your PC with one as well it having battery backup for use during outages/brownouts and fluctuations, you can also plug in other stuff such as your router and other sensitive equipment.

[Bad 💀 Motha]

And most appliances also aren't on for very long and are mostly used to produce a heating effect for a short period of time, or to simply provide power to work something mechanical (like a mixer, shredder, etc.) it's just not the same thing at all.

[A&A]

Someone needs to convert the AC (220/110V) to DC (3.3, 5 and 12V) and the process be safe to not fry your RTX4090, they come with extra circuits that can protect it from unusual things like over/under voltage, overcurrent, PSU heats up toooooo much to the point of max operating temperature (same as CPU and GPU) and if for some reason you've melted the 4090 after extreme OC. Yes, a short circuit can make any PSU made in a Taiwanese basement explode (I mean no brand 10 bucks PSUs)
It is cheaper to have all of these safeguards in one place rather than everywhere, so you won't burn everything down.

Light bulbs (modern LEDs) are better suited for direct current, otherwise they will light up and black out 50 times per second, simply because the nature of the transistor is to allow current to flow in one direction. That's why they have a bridge reactifier.

Meanwhile heaters and incandescent bulbs don't care if it is gonna be alternating current or direct current. Thermal current is the key.

But yes, PC parts in general don't require a lot of raw resources while having a huge amount of added value.

[_I_]

pc power supplies (psu) do cost more than they did a 5+ years ago
but they are more efficient now, and also higher current

newer cpus and gpus need more current than they did 5+ years ago

mains/outlet power is 110-220v ac (alternating current, not active, swapping polarity which is much more efficient to transfer power across very long distances)

cpu, gpu, usb, drives etc, run on 1.xv, 3.3v, 5v, 12v dc (direct current) and need to stay in fairly tight spec

basic math
watts = volts x current

the psu does do filtering and regulating at the output voltages
first thing is first
it takes the 110-220v, does some filtering to clean it a bit,
then uses a bridge to convert it to 200-500v dc
and chops that up at a high frequency and uses a small transformer to convert it to lower voltage and then bridge to dc and then regulates that for its output voltages

it also has monitoring circuitry to watch for power spikes, and tells the board that the power is ok

most cpus and gpus need 60-300+w @ ~1v , pc power supply do not output 1v, the mobo or gpu board have a buck converting circuit to convert the 12v to the 1v needed for their cpu/gpu core

never cheap out on a power supply
its the one component that can save everything else if all goes wrong
poor ones will spike rails and output enough ripple/noise in the lines to kill gpu, mobo drives and anything attached when overloaded or if its overrated and not up to the task

[smokerob79]

I love the fact all new power supplies are only based on the 12 volt rail.....no more PSU's saying 600 watts with a 350 watt 5volt rail.......

[Bad 💀 Motha]

smokerob79님이 먼저 게시:

I love the fact all new power supplies are only based on the 12 volt rail.....no more PSU's saying 600 watts with a 350 watt 5volt rail.......

And when do you remember that being that way?

On a decent Gold/Platinum 750 Watt even from 10 years ago; the 12V was rated @ approx 740-750 Watts while the 3.3V + 5V had a combined rating @ approx 150 Watts

So your math is little off there bud.

Even when I go back and look at older stuff such as ATX 2.3 / Thermaltake TR2 450W; while this did have 2x 12V Rails; out of that 450W it states 120W Max for the 3.3V + 5V combined still.

[_I_]

smokerob79님이 먼저 게시:

I love the fact all new power supplies are only based on the 12 volt rail.....no more PSU's saying 600 watts with a 350 watt 5volt rail.......

they were never like that

there are a few 12vo power supplies with only 12v, no minor rails but the board has to be specifically made for them and convert the power to make all the minor rails for drives usb and other stuff

20+ years ago power supplies needed much stronger 5v since the cpus ran on the 5v only hdds needed 12v
now mobo and gpu need 12v

[Tonepoet]

You can spend hundreds of dollars on a power supply, but you don't really have to do so.

There isn't reallly a card on the market that needs more than a thousand watt power supply. The advertised rating for a power supply is continuous power draw. Peak power draw is usually expected to be around 30% higher than its continuous power rating on most power supplies[www.cybenetics.com], and even the cheapest $30 thermaltake power supply could handle peaks in excess of 35% of its power rating

There are formalized standards for peak power draw starting with A.T.X. 3.0[edc.intel.com]

Even top of the line power hog systems like this $3750 Corsair i7500 Vengence i7500 with an RTX 4090 and a 14900k[www.corsair.com] do not need more than 1000 watts of power, so you can just get Be Quiet Pure Power 12 M 1000W]away with spending $130 on an ATX 3.1 compliant pure power 12M 1000 watt power supply[www.amazon.com]. Even at M.S.R.P. of $165 that power supply doesn't quite cost hundreds.

Considering that laptop chargers from the likes of Razer[www.razer.com], Dell[www.apple.com] can cost $80-100 it isn't particularly unreasonable that a system which requires much higher power draw.

Right now you can buy an A.T.X. 3.1 Pure Power 12 M 1000W for just $130[www.amazon.com]

Most computers do not need a power supply anywhere near that powerful. This M.S.I. Mag A750GL only costs $90 at the moment[www.amazon.com], and it will suffice to power most computer configurations, including 4070 ti based systems.[www.corsair.com]

Some people pay more for extra efficient power supplies, because the savings on the electrical bills add up over time, and a power supply is one of the most future proof P.C. components.

Other people pay extra for the peace of mind a quality power supply provides them. Nobody wants to spend $1700 on a G.P.U. and $600 on a processor only to blow up their entire system because they bought a $30 P.S.U. that wasn't meant to handle anywhere near the power requirements those things need.

And yeah, desktop computers can have much more performance than laptops, sometimes even at cheaper prices, in part because they are not restrained to the confines what can be drawn from battery power. More power equals more power. Who knew?

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?

Most of those products have a power supply of some sort inside of them. Almost everything that plugs into the wall has a power supply. Sometimes the power supply is built into the device, in which case the end user never sees it. Other times the power supply is attached to the cord you plug into the device that's why the wall wart is so chonky, and why the gamecube cord has a box on it. The laptop's power supply is the charger, though the laptop has some additional circuitry inside of it too.

NeBaZ-)님이 먼저 게시:

it's not a converter.

Power is put into the capacitors switched from active to direct and pulled slowly through regulation.

No. It is a converter. It converts the power from the wall into the power needed by the device. It converts A.C. to D.C. It also converts high voltage to low voltage through the power regulation process. Thing is conversion isn't necessarily a simple or easy process as it sounds.

[A&A]

Yep _I_ explained all steps of а PSU's work. Although from an inquisitive point of view I find the pattern of actions a bit strange, but there is most likely something I don't know. Wizard ;D

[smokerob79]

the standard was changed for Haswell CPU's......but never mind real facts and history you people missed......power supplies before Haswell were all calculated by total watts across all rails added together.....most power supplies made now are only 12 volt with DC to DC converters.....we no longer have 3 power supplies taking 120 volts AC to their respected voltages on the DC side.....


lie all you want you people dont understand power supplies.....

[PopinFRESH]

this entire thread is quite sad

[PopinFRESH]

smokerob79님이 먼저 게시:

the standard was changed for Haswell CPU's......but never mind real facts and history you people missed......power supplies before Haswell were all calculated by total watts across all rails added together.....most power supplies made now are only 12 volt with DC to DC converters.....we no longer have 3 power supplies taking 120 volts AC to their respected voltages on the DC side.....


lie all you want you people dont understand power supplies.....

Would you happen to have any actual facts you could share? such as a circuit diagram of one such PSU that had 350W on a 5v rail? I don't see that you've posted any facts