News Nvidia's RTX 5090 power cables may be doomed to burn

[Admin]

A rising tide of speculators are arguing that Nvidia's 16-pin 12VHPWR standard is designed with no safety factor, causing melting cables.

Nvidia's RTX 5090 power cables may be doomed to burn : Read more

 

[valthuer]

That's what happens when you fail to properly plug in the power cable.

 

[emgarf]

Resistors in series are not "shunt" resistors.

 

[vanadiel007]

Resistors in series are not "shunt" resistors.

That is because they are not actually resistors, but shunts. They have a very low resistance and therefore a very low voltage drop in relationship to the current flowing through them.

In the old days they were used to directly drive volt and amp gauges, often using a signal that would produce millivolts per amp flowing though it.

 

[InvalidError]

That's what happens when you fail to properly plug in the power cable.

derB properly plugged his cable. Still got to 150C from most of the current going through only two wires, likely because the connector at one or possibly both ends was worn out and those two wires were the last ones still in decent shape.

 

[TJ Hooker]

Resistors in series are not "shunt" resistors.

That was my thought too, but apparently it is a commonly used term for current sense resistors in VRMs. E.g. https://www.ti.com/content/dam/vide...choose-a-shunt-resistor-presentation-quiz.pdf

 

[TheyStoppedit]

Since the very first 4090 melt, very simple reasoning would have told you this is not, and never was "User error" as NVidia and GN tried to claim. I still remember the very first time I laid eyes on those tiny little 12 pins.... and saw "600W"..... and I was like.... ummmm... lol.... this has to be an april fools prank!!! Lol...... this is.... not going to end well. Basic high school electricity can tell anyone this is just not happening lol. But that's okay..... Leaving it to a $2T company with probably thousands of highly experienced electrical engineers to fail a grade 9 electricity test when it actually matters. Give your head a shake *takes another mouthful of popcorn* Lol.

Sigh.... ya know.... if we had just stuck with our regular, well established, well matured, tried, tested, and true.... trusty 8-pin connector that has never let us down, none of this would have ever happened. As the old adage goes, if it aint broke, dont fix it. Lesson learned NVidia, lesson learned

 

[Gururu]

I think it is important that hardware review sites cover this and put the challenge to nVidia to address it.

 

[InvalidError]

Resistors in series are not "shunt" resistors.

Shunt is a function, not a component. It is something that is parallel with another to divert flow around. For example, the shunt resistor in old-school analog current meters is in parallel with the dial indicator and calibrated for full-scale at maximum rated current.

You can have resistive shunts (resistors), capacitive shunts and inductive shunts depending on what you want to achieve and how.

Resistors designed specifically for precision current measurement have dedicated sense pads to measure voltage across the resistor from inside the SMD terminals to eliminate high-current solder joints from measurements. If you only need rough measurements, having a sense trace tap the middle of the solder pads with an ordinary low-value resistor is often good enough.

 

[DingusDog]

I'll stick with tried and true 3x8 pins for the foreseeable future thank you very much.

 

[lmcnabney]

I'll stick with tried and true 3x8 pins for the foreseeable future thank you very much.

That way you will have nine +12V wires providing power instead of just six.

 

[sillysaxon]

I don't get the new connectors anyway, you end up with a y splitter to plug in multiple rails.
I would rather just plug them both into the card directly if that's what it takes, the tiny pins can't physically handle that much electrical draw at 12v.
600W/12V=50A
Ampacity charts will say 50A starts at 8Ga wire! No way these baby pins stand a chance

 

[jp7189]

I'll stick with tried and true 3x8 pins for the foreseeable future thank you very much.

8 pin spec is rated for 150watts each. You'd need 4x8pin for a 5090 even though that's 12x 12v supply wires vs 6x 12v in the 12vh connector

 

[jp7189]

I don't get the new connectors anyway, you end up with a y splitter to plug in multiple rails.
I would rather just plug them both into the card directly if that's what it takes, the tiny pins can't physically handle that much electrical draw at 12v.
600W/12V=50A
Ampacity charts will say 50A starts at 8Ga wire! No way these baby pins stand a chance

There are 6 wires carrying +12v, so you'd need to divide 50 amps by 6... unless something goes wonky and all 50 amps gets crammed down a single wire for some reason.

 

[Franknj229]

So what's the bottom line? I'm not an electrical engineer. Everybody is talking about the problem, but is there a solution? I'm waiting on the 5090s to come back in stock so I can build a high-end pc. Should I bother? Is it just going to destroy itself as soon as I try to use it?

 

[valthuer]

I'm waiting on the 5090s to come back in stock so I can build a high-end pc. Should I bother? Is it just going to destroy itself as soon as I try to use it?

If you ask me, go right ahead.

I can recall people having worries about 4090 being dangerous and it was MASSIVELY blown out of proportion.

Isolated incidents and user errors, will always occur.

That shouldn't stop you from buying what you really want.

 

[Jabberwocky79]

Isolated incidents and user errors, will always exist.

As many others have stated, people didn't suddenly forget how to plug in a cable correctly when the 40 series dropped. This goes far beyond user errors.

 

[YSCCC]

That's what happens when you fail to properly plug in the power cable.

View: https://youtu.be/6FJ_KSizDwM?si=W1nE8zKGorwfKVPw


Jay have found something.
Welcome to quantum physics, Schrödinger might have ditched his cat and not it’s Schrödinger’s plug! You will not know if your plug contact have backed out a bit during insertion until it smokes

https://twitter.com/x/status/1890090230566244366

View: https://x.com/jayztwocents/status/1890090230566244366?s=46

 

[About30Ninjas]

Best free marketing for AMD GPUs - "I don't want my $2000 video card to potentially go up in smoke".
Any AMD video card will always be faster than a toasted Nvidia card. 😉

 

[Mr Majestyk]

8 pin spec is rated for 150watts each. You'd need 4x8pin for a 5090 even though that's 12x 12v supply wires vs 6x 12v in the 12vh connector

Its spec is 150W but with 90% safety margin so I'll bet could handle 200W sustained. 3 8 pin connectors and pci-e slot could provide 675W and still have 200W up it's sleeve as safety margin.

 

[YSCCC]

Its spec is 150W but with 90% safety margin so I'll bet could handle 200W sustained. 3 8 pin connectors and pci-e slot could provide 675W and still have 200W up it's sleeve as safety margin.

Or just get those industrial grade 8pin which are used in seasonic/corsair PSUs, those are rated 300W each with massive overhead also, if power delivery is such a big issue how about not drinking so much

 

[Li Ken-un]

Any AMD video card will always be faster than a toasted Nvidia card. 😉

Smoking fast versus smoking 😂

 

[ingtar33]

If you ask me, go right ahead.

I can recall people having worries about 4090 being dangerous and it was MASSIVELY blown out of proportion.

Isolated incidents and user errors, will always occur.

That shouldn't stop you from buying what you really want.

that was with tens of thousands in circulation. the circulation of 5090s is likely much much smaller. from what could be seen it's likely there is no more then 1000 in circulation right now. and credible reports of at least 10 have melted down. that's a titanic 1% failure rate. that might not sound high but when you're dealing with a product in the wild for less then a month thats a horrifying number, because as time passes that failure rate will increase logarithmically.

 

[JTWrenn]

I wonder if the problem with these really is just that the size of the pins and their housing is too small so they don't stay seated right. That coupled with less protection and poof melted cable. Maybe the simples answer is a seated cable light on boards to tell you everything is in place, or something similar.

Of course the other option of going to bigger ports and just double stacking the things seem to make the most sense to me. Go back to bigger dual 8s. They worked better end of story.

Wonder if nvidia is gonna get sued at some point here.

 

[YSCCC]

If you ask me, go right ahead.

I can recall people having worries about 4090 being dangerous and it was MASSIVELY blown out of proportion.

Isolated incidents and user errors, will always occur.

That shouldn't stop you from buying what you really want.

A funny fact is now in reddit, ppl have 4090s working perfectly since release now is getting interested/panicking and pull out the plug to inspect, and quite some have found parts of the plug melted/melting but still barely working, why we have to pay and enjoy all the smoke