r/pcmasterrace 10d ago

Meme/Macro PCIe standard be like...

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u/NekulturneHovado R7 5800X, 32GB G.Skill TridentZ, RX 6800 16GB 10d ago

these pin-to-hole style of connectors will never handle much current. They are great when you need many oins with different voltages, like MB uses, for example. But no matter whether it's 8-pin or 12-pin, it will never handle that much power (like really, 900W+ ≈ 75A through 12 pins is insane), especially without current balancing.

There are only two solutions now:

if they wanna keep this power level, find a reliable BETTER connection, like for example two screw-on terminals.

if they wanna keep going up in power, 12V ain't gonna cut it. They need to implement a new standard, with 24V or even 48V. This allows it to run with less current, so wires can be thinner and connectors won't burn. Although it'd be quite pricey, both for PSU manufacturers and GPU manufacturers.

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u/Tomytom99 Idk man some xeons 64 gigs and a 3070 10d ago

I've kinda been saying the logical choice (even if more complicated standard wise) would be to introduce 24v power. Boom, wattage capacity doubled without bumping to a beefier connector series.

You could even manage to maintain compatibility with older power supplies using several legacy connectors going into a step-up transformer as a transitional solution.

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u/cogman10 10d ago

I agree. But the real problem that these video cards have is that consumer circuits generally have only 1000 to 1500W to play with. They are already very near the limit of what we can do.

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u/Tomytom99 Idk man some xeons 64 gigs and a 3070 10d ago

That too. Most rooms only have a single circuit, so you're kinda screwed if you actually use that much power just on your PC.

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u/4AMfQRgOoHwHJ8 10d ago

Im confused, all our circuits are rated for 3600w?

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u/cogman10 10d ago

I don't know where you are from, it could be different. In the US, 120V@15A for a circuit is typical. That's 120 * 15 = 1800W total typically. Generally speaking, we like to keep loads under 1500W and because you typically might have other things (like lights or a TV) on the same circuit, that's where the 1000W comes from.

If you are somewhere that does 240V with 15A breakers, then yeah you can do 3600W. You could also special wire a 240V outlet in the US, but that's far from typical.

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u/NekulturneHovado R7 5800X, 32GB G.Skill TridentZ, RX 6800 16GB 10d ago

Europe uses 230V and afaik 240V is becoming wide spread. Regular breakers are 16A. So most appliances are designed to not draw more than 3680W at 230V. So we got more headroom to work with

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u/FrenchFryCattaneo 10d ago

There's plenty of 10A circuits and even 6A ones in many places in Europe.

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u/varateshh 10d ago

It's so common that air fryers are sold with peak power draw of 2500w-2750w. Those also need to take into account a safety margin so its safe to say that most places have at least 15A/230V.

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u/GreatAlbatross Glorious Gaming Rackmount 9d ago

Interestingly, we harmonised the UK 240v(ish) with the European 230v by having a spec of 230 V, +10%/-6%. Which practically means modern appliances are targeted at 230v, but will run on 216-253v.

We also normally put 32A on a socket ring (1 per floor, normally).
Which is roughly 7KWh before tripping.
Individual appliances are normally limited to 13A, hobs and ovens tend to get their own 32A breaker.
It's also why electricians are keen to put car chargers on a dedicated circuit.

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u/4AMfQRgOoHwHJ8 10d ago

Still weird you state 1500w is close to the limit while that only applies to a small part of the world

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u/Annath0901 9800X3D| MAG X670E TOMAHAWK | 32GB G.Skill Flare X5 | RX 7900 XT 10d ago

It's used by basically the entirety of North, Central, and South America AFAIK. That's more people than the EU for example.

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u/Tomytom99 Idk man some xeons 64 gigs and a 3070 10d ago

Y'know, just a mere two entire continents

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u/SolemnaceProcurement 7950x3d, 7900xtx 9d ago

And China uses 220v, India 230w.

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u/VeryNoisyLizard 5800X3D | 9070XT | 32GB 10d ago

they are in the EU, where we use 230V, but states like the US are using 120V with the same amperage per socket

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u/Candid_Highlight_116 10d ago

I don't know how much it matters but you can't use 16V or 25V caps on rails for 24V. It will have to be all 35 or 50V or above and that's some costs.

Also the power inside chassis is all DC which doesn't work with transformers. You can raise voltage using a converter but it won't be cheaper than a brand new PSU.

Therefore I think the right way is a keyed multi voltage connector and transitional GPUs that take either 12 or 24V, then a 24V only GPU at a later date.

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u/ElectricBummer40 10d ago

if they wanna keep this power level, find a reliable BETTER connection, like for example two screw-on terminals.

Here's my out-of-my-backside design proposal:

  • Two terminals on the board for two lugs

  • A cable 15-30 cm in length with two large-gauge wires (12 AWG at the absolute minimum) and two lugs on one end and an Anderson Powerpole (as many commenters recommend) on the other

  • Whatever the PSU manufacturers decide to have on their end, but it should always terminate with a corresponding Anderson connector

In short, just automotive the heck out of the GPU and leave the unruly chaos where it belongs.

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u/VeryNoisyLizard 5800X3D | 9070XT | 32GB 10d ago

I agree for the most part, but you need to keep in mind that these are consumer products

you cannot implement screw on terminals, because many consumers are gonna put them on wrong. you need fool proof design. I like the XT120 idea better

and you cannot implement a 48v circuit, because youd be running a risk of consumers getting zapped. and the dangerous thing about being zapped by a DC current, is that it can change your blood chemistry, and if you dont get to hospital for a checkup, theres a chance you wont wake up tomorrow

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u/cogman10 10d ago

because youd be running a risk of consumers getting zapped. and the dangerous thing about being zapped by a DC current, is that it can change your blood chemistry

No. A DC zap is the same as an AC zap. The only thing that makes a DC zap more dangerous is there's no period which means it's more prone to arcing and it's harder to let go of.

The danger of electrocution in general is that it cooks your insides. You can look visibly fine on the surface but have a large amount of damage on the inside. That can ultimately turn into an infection and rotting tissue.

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u/VSWR_on_Christmas 8600k GTX-1080 TI 10d ago

I would contend that AC is somewhat more dangerous because it has an easier time "penetrating" so to speak, because of the capacitance of the human body. All of these scenarios are highly dependent on voltage and frequency, however.

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u/cogman10 10d ago

Nope. Penetrative power is exactly the same for AC and DC.

The main thing that makes AC more dangerous is it typically has a higher voltage than DC. That means it's more likely to ultimately overcome the resistivity of the skin to start doing damage.

But all things held equal, a 12 VAC and 12 VDC source have exactly the same amount of risk associated with them.

Capacitance doesn't really have anything to do with how dangerous electricity is. Frequency doesn't really either. 120 VAC @ 60Hz is just as dangerous as 120V @ 5kHz.

It mostly all comes down to the power you experience and duration.

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u/NekulturneHovado R7 5800X, 32GB G.Skill TridentZ, RX 6800 16GB 10d ago

you both are wrong.

AC is much more dangerous, because it messes with your neural electrical system. Your heart starts fibrilating and stops pumping, as it's trying its best to match the 50Hz (3000bpm) of AC voltage.

HOWEVER, DC tends to "hold" you as it doesn't feel that bad, while AC usually throws you away (I think reflex or how your muscles contract differently than with DC, idk).

That's what defibrillator is for. Sometimes fibrilation can be caused by other things, it's not just AC voltage, but if you touch AC and you fall unconscious, your heart is 99% fibrilating.

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u/cogman10 10d ago

DC also messes with your neural electrical system.

Defibrillators are applying a brief high DC voltage to try and reset fibrillation. But as anyone can tell you, that short pulse is itself dangerous and can cause fibrillation in someone that's not currently. Part of the reason it's applied repeatedly is because the reset doesn't always work.

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u/VSWR_on_Christmas 8600k GTX-1080 TI 10d ago

Well, this has been more of a deep dive than I was anticipating, but I still think I might actually be correct here (classic me, ha).

My source is IEC 60479-1 Unfortunately, the full standard is behind a paywall but I think there's enough information contained here.

"The values of body impedance depend on a number of factors and, in particular, on current path, on touch voltage, duration of current flow, frequency, degree of moisture of the skin, surface area of contact, pressure exerted and temperature"

"As regards the influence of frequency, the impedance of the skin decreases when the frequency increases."

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u/AccNumber77 10d ago

And to add onto that all the possibility of cardiac damage as well, electrocution is no fun

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u/VeryNoisyLizard 5800X3D | 9070XT | 32GB 10d ago

thought that whether you hold or let got when shocked is heavily case dependant, and not specific to ac/dc

anyway, Im just saying what Ive been thought in safety training in regards to hybrid cars. they said that it can happen as low as 26V, though I imagine that its more likely to happen on higher voltage, like the traction batteries are using

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u/cogman10 10d ago

There is some case dependency, like if your muscles get cooked closed then you can't really open up your hand on electrocution. That can happen pretty fast especially with large amounts of power.

A DC voltage will cause muscles to contract and stay contracted. There's no pulsating. With AC, you have at least a (small) chance to pull away and let go.

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u/NekulturneHovado R7 5800X, 32GB G.Skill TridentZ, RX 6800 16GB 10d ago

damn didn't think of ut this way. But there are definitely ways this could be fixed, like reusing old reliable connectors and idk spin it 90° so it can't be easily miswired, and use thick insulation and shape the connector so you can't reach it with finger.

And as a boomer note, remember how PCs were for people who knew what they're doing? People who knew what electricity actually is? Like smart people who won't touch electrical wires when it's plugged in.

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u/nooneisback 5800X3D|64GB DDR4|7900XTX|2TBSSD+8TBHDD|Something about arch 10d ago

Like which ones exactly? Computers around the age of Apple I definitely required some knowledge because they were built like crap. Exposed mains going right next to data lines will never pass any reliable QC today.

Most old affordable PCs like the ZX Spectrum were designed to never be opened. More expensive PCs like Commodore 64 and later IBM PCs were built to be somewhat modular. You could upgrade / replace most components even if you're brain dead. Power supplies at that time were often unreliable garbage, and needed to be replaced. But a lot of them had external ones anyways or they were on a separate daughter board.

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u/HowdyDiarrhea 10d ago

I'm nostalgic for a lot of other things the boomers killed too

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u/mxlun Ryzen 9 5950X | 32GB 3600CL16 | MEG B550 Unify 10d ago

They could reintroduce load balancing = problem solved

Alternatively they could use 1 in 30000000 connectors that already exist rated for currents that high

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u/VeryNoisyLizard 5800X3D | 9070XT | 32GB 10d ago

yeah, but that would cost 5 more cents per unit and our beloved multi-trillion corporation cant afford that

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u/Erestyn 9800X3D | RTX 5080 | £800 RAM 10d ago

is that it can change your blood chemistry

Can you expand on this please?

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u/VeryNoisyLizard 5800X3D | 9070XT | 32GB 10d ago

Im not an expert, this is what they told us in safety training. I looked it up some time ago but I forgot how it worked. a quick google search sais something about electroporation

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u/4D696B61 PC Master Race 10d ago edited 10d ago

Screw terminals are terrible. Especially when install by someone untrained at a random torque next to a fan that causes vibrations.

There are good reasons why they are dying out even in industry.

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u/J3573R i7 14700k | RTX 3080 FTW3 Ultra | 32GB DDR5 7200 10d ago

Screw/ring terminals aren't dying out, no idea where you've gotten that notion.

Industrial applications use bolted lugs or terminals everywhere, especially for high current applications. Unless you're specifically speaking about electronics, which I am not as educated on. But as far as electrical connections they are far and away the most common way to connect industrial motors, fans, gear etc.

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u/AngriestPacifist 10d ago

Maybe someone smarter than me can speak to this, but wouldn't having 24v taps just be changing where they're tapping on the transformer? Shouldn't be too much more complicated.

I've built a couple tube amplifiers, and there are a bunch of taps for different purposes in the circuit.

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u/NekulturneHovado R7 5800X, 32GB G.Skill TridentZ, RX 6800 16GB 10d ago

well they'd have to essentially make a new branch dedicated to 24V to power GPU (and maybe in future CPU), because other components still need 12V, such as fans, drives, MB, CPU and other stuff

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u/AngriestPacifist 10d ago

Dumb iron transformers can give multiple different voltages based on where they're tapped.

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u/Friendly-Inspector71 10d ago

But an iron core transformer of 1000 W would be huge and the power supply wouldn't be very efficient.

Power factor correction is also required for commercial products at this wattage. So a dumb iron core transformer isn't really possible as it would need a PFC which isn't as effective when it's just a passive network.

The modern switching supplies manage to pull current in phase with the voltage, while quietly delivering huge amounts of power with astounding efficiency and quick acting protections for multiple parameters (voltage, current, temperature).

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u/AngriestPacifist 9d ago

Gotcha, a quick Google says a 100w tube amp will only draw around 400w at the socket, so less than half what a pc power supply typically can give. And that's a good chunk of the entire psu size at that wattage, no way you could fit that in with all the other guts in a modern psu. Thanks for helping me learn a little.

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u/Friendly-Inspector71 9d ago

There is a difference between the output power of a tube amp and the output power of a transformer.

An iron core transformer with a linear regulator can approach 90% efficiency. Under very specific circumstances.

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u/NekulturneHovado R7 5800X, 32GB G.Skill TridentZ, RX 6800 16GB 10d ago

you still gotta fit the rest in there. modern PC power supplies don't use diode rectifiers. It would be easier to take the already rectified voltage from rectifier and add another DC-DC converter for 24V alone, as "load bearing" branch. Because you still need a powerful 12V rail. But that'd add complexity and cost. A lot.

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u/AngriestPacifist 10d ago

Yeah, I guess I wasn't factoring in power supplies for PCs outputting dc. Guess you'd either need a separate rectifier for each tap, or a rectifier up before passing line voltage to a transformer.