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Nvidia's RTX 5090 power connectors are melting

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Re: Nvidia's RTX 5090 power connectors are melting

#301

Post by singleshot_ »

mminer237 wrote: post #153
dcrazy wrote: post #120

Is NVIDIA breaching any consumer safety laws by pumping twice the rated current through a 24ish gauge wire? Perhaps by violating their UL certification?

UL is a private company. There're no laws requiring it or penalizing violations. I would think the only legal consequences would be through civil product liability/breach of warranty claims. Plus, like, losing the certification would mean most stores would no longer stock it.

Seems like if you filled your house with non-UL compliant stuff and your house burned down, the first fact would be material to your insurance carrier (you know, the Underwiter to which the UL name refers…)

Re: Nvidia's RTX 5090 power connectors are melting

#302

Post by nvarsj »

I would love to get some insight from Nvidia engineers on what happened here.

The 3 series and before were overbuilt in their power delivery system. How did we get from that to the 1 shunt resistor, incredibly dangerous fire-hazard design of the 5 series? [1] Even after the obvious problems with 4 series, Nvidia actually doubled down and made it _worse_!

The level of incompetence here is actually astounding to me. Nvidia has some of the top, most well paid EE people in the industry. How the heck did this happen?

1: https://www.youtube.com/watch?v=kb5YzMoVQyw

Re: Nvidia's RTX 5090 power connectors are melting

#304

Post by wtallis »

truncate wrote: post #261
rollcat wrote: post #242

Earlier quoted context omitted.

Can we talk about how absolutely terrifying is that 600W figure? We're not transcoding or generating slop as the primary use case, we're playing computer games . What was wrong with the previous-generation graphics that we still need to push for more raw performance, rather than reducing power draw?

Is the primary use case for *090 series gaming anymore? 5070 which is probably what most popular gaming card is 250W. If I recall correctly it can push 4k @ 60fps for most games. But yes, I do agree that TDPs for GPUs are getting ridiculous.

4k 60Hz is still largely unachievable for even top of the line cards when testing recent games with effects like raytracing turned up. For example, an RTX 4090 can run Cyberpunk 2077 at 4k at over 60fps with the Ray Tracing Low preset, but not any of the higher presets.

However, it's easy to get misled into thinking that 4k60 gaming is easily achieved by more mainstream hardware, because games these days are usually cheating by default using upscaling and frame interpolation to artificially inflate the reported resolution and frame rate without actually achieving the image quality that those numbers imply.

Gaming is still a class of workloads where the demand for more GPU performance is effectively unlimited, and there's no nearby threshold of "good enough" beyond which further quality improvements would be imperceptible to humans. It's not like audio where we've long since passed the limits of human perception.

Re: Nvidia's RTX 5090 power connectors are melting

#305

Post by mjevans »

zamalek wrote: post #290
kersplody wrote: post #273

12vhpwr has almost no safety margin. Any minor problem with it rapidly becomes major. 600W is scary, with reports of 800W spikes. 12V2x6 is particularly problematic because any imbalance, such as a bad connection of a single pin, will quickly push things over spec. For example, at 600W, 8.3A are carried on each pin in the connector. Molex Micro-Fit 3.0 connectors are typically rated to 8.5A -- That's almost no margin…

> Any imbalance I watched de-Bauer's analysis this morning, and you've seemingly hit the nail on the head. Even on his test bench it looks like only two of the wires are carrying all of the power (instead of all of them, I think 4 would be nominal?) - using a thermal camera as a measuring tool. The melted specimen also has a melted wire. Maybe 24V or 48V should be considered, and higher gauge wires - yes.

It would be _lovely_ if instead of the 12V only spec we went to 48V for internal distribution. Though that would require an ecosystem shift. USB-PD 2.0~3.0 would also be better supported https://en.wikipedia.org/wiki/USB_hardware#USB_Power_Deliver...

As others no doubt mention Power (loss, Watts) = I (amsp) * V (volts (delta~change on the wire)).

dV = I*R ==> dV = I * I / R -- That is, other things being equal, amps squared is the dominant factor in how much power loss occurs over a cable. In the low voltage realms most insulators are effectively the same and there's very little change in resistance relative to the voltages involved, so it's close enough to ignore.

600W @ 12V? 50A ==> 1200 * R while at 48V ~12.5A ==> 156.25 * R

A 48V system would have only ~13% the resistive losses over the cables (more importantly, at the connections!); though offhand I've heard DC to DC converters are more efficient in the range of a 1/10th step-down. I'm unsure if ~1/25th would incur more losses there, nor how well common PC PCB processes handle 48V layers.

https://en.wikipedia.org/wiki/Low_voltage#United_States

""" In electrical power distribution, the US National Electrical Code (NEC), NFPA 70, article 725 (2005), defines low distribution system voltage (LDSV) as up to 49 V.

The NFPA standard 79 article 6.4.1.1[4] defines distribution protected extra-low voltage (PELV) as nominal voltage of 30 Vrms or 60 V DC ripple-free for dry locations, and 6 Vrms or 15 V DC in all other cases.

Standard NFPA 70E, Article 130, 2021 Edition,[5] omits energized electrical conductors and circuit parts operating at less than 50 V from its safety requirements of work involving electrical hazards when an electrically safe work condition cannot be established.

UL standard 508A, article 43 (table 43.1) defines 0 to 20 V peak / 5 A or 20.1 to 42.4 V peak / 100 VA as low-voltage limited energy (LVLE) circuits. """

The UK is similar, and the English Wikipedia article doesn't cite any other country's codes, though the International standard generally talks at the power grid distribution level.

Re: Nvidia's RTX 5090 power connectors are melting

#306

Post by sidewndr46 »

mminer237 wrote: post #153
dcrazy wrote: post #120

Is NVIDIA breaching any consumer safety laws by pumping twice the rated current through a 24ish gauge wire? Perhaps by violating their UL certification?

UL is a private company. There're no laws requiring it or penalizing violations. I would think the only legal consequences would be through civil product liability/breach of warranty claims. Plus, like, losing the certification would mean most stores would no longer stock it.

You might want to do some research on what you can buy and legally plug into your own home. It's more or less you get UL listing, or the product isn't available

Re: Nvidia's RTX 5090 power connectors are melting

#307

Post by Ygg2 »

zamalek wrote: post #296
tcdent wrote: post #285

Earlier quoted context omitted.

This is the most informative assessment in this thread. You'd expect to see the capacity to be 125% as is common in other electrical systems. Ratings for connectors and conductors comes with a temperature spec as well, indicating the intended operating temperature at a load. I'm sure, with this spec being near the limit of the components already, that the operating temperatures near full load are not far from the lim…

"3rD party connectors" is being waved around by armchair critics. The connectors on the receiving end of all of this aren't some cheap knock-off, they are from a reputable manufacturer and probably exceed the baseline.

No sane individual is going to buy 5090 for $2000-100000 and hook it up to a $15 Power supply.

Re: Nvidia's RTX 5090 power connectors are melting

#308

Post by crote »

zamalek wrote: post #290
kersplody wrote: post #273

12vhpwr has almost no safety margin. Any minor problem with it rapidly becomes major. 600W is scary, with reports of 800W spikes. 12V2x6 is particularly problematic because any imbalance, such as a bad connection of a single pin, will quickly push things over spec. For example, at 600W, 8.3A are carried on each pin in the connector. Molex Micro-Fit 3.0 connectors are typically rated to 8.5A -- That's almost no margin…

> Any imbalance I watched de-Bauer's analysis this morning, and you've seemingly hit the nail on the head. Even on his test bench it looks like only two of the wires are carrying all of the power (instead of all of them, I think 4 would be nominal?) - using a thermal camera as a measuring tool. The melted specimen also has a melted wire. Maybe 24V or 48V should be considered, and higher gauge wires - yes.

> I think 4 would be nominal?

6 or 12, depending on how you count. There are 6 12V supply wires, and 6 GND return wires. All of them should be carrying roughly the same current - just with the GND wires in the opposite direction from the 12V ones.

Re: Nvidia's RTX 5090 power connectors are melting

#309

Post by 0x457 »

truncate wrote: post #261
rollcat wrote: post #242

Earlier quoted context omitted.

Can we talk about how absolutely terrifying is that 600W figure? We're not transcoding or generating slop as the primary use case, we're playing computer games . What was wrong with the previous-generation graphics that we still need to push for more raw performance, rather than reducing power draw?

Is the primary use case for *090 series gaming anymore? 5070 which is probably what most popular gaming card is 250W. If I recall correctly it can push 4k @ 60fps for most games. But yes, I do agree that TDPs for GPUs are getting ridiculous.

4k@60 isn't all that good today and 5070 can do it with reduced graphics in modern games.

x90 cards IMO are either bought by people that absolutely need them (yay market segmentation) or simply because they can (affording is another story) and want to have the best of the latest.

Re: Nvidia's RTX 5090 power connectors are melting

#310

Post by 0x457 »

jgalt212 wrote: post #288
jorgemf wrote: post #251

Earlier quoted context omitted.

This genereation seems that is getting performance using more power and more cores. Not really an architectural change but only packing more things in the chip that require more power.

Too true. I've been looking replace my 1080. This was a beast in 2016, but the only way I can get a more performant card these days is to double the power draw. That's not really progress.

That's because 1080 and whole 10xx generation was pinacle and is the best GPU nvidia ever made. Nvidia won't make the same mistake any time soon.
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