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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

#191

Post by lr1970 »

DannyBee wrote: post #97
Havoc wrote: post #77

What’s wild is that this is a company clearly capable of designing highly complex things with numerous tradeoffs, challenges and unknowns. And then the fuckin cable is the issue. Repeatedly.

This is because they are trying to parallel like 50amps (it's 12 volt IIRC) over a few conductors to get to 600watts. If it becomes unbalanced due to any number of reasons, none of those individual cables can come close to handling it - they will all generate enough heat to melt lots of things. Conservatively, they'd have to be 8awg each to be able to handle the full load without melting if they ended up taking the f…

> If the voltage was higher (i believe 'low volt' classification tops out at 48v)

Yep, 48V through sensitive parts of the body could be unpleasant but 24V is almost as safe as 12V. Why didn't they use 24V and 25A to achieve required 600W of power instead of 12V and 50A?

Re: Nvidia's RTX 5090 power connectors are melting

#192

Post by mrguyorama »

seanw444 wrote: post #137
Hamuko wrote: post #127

Earlier quoted context omitted.

I had two AMD 7900 XTX and they both overheated like mad. Instant 110°C and throttle. Opted for a refund instead of a third GPU.

Probably reference cards, yeah? I think the common advice is to not buy the reference cards. They rarely cool enough. I made that mistake with the RX 5700 XT, and will never again.

My 5700XT overheated constantly. It wasn't a reference card. The problem was that the default fan curve in the driver maxed out at 25%!

AMD is REALLY bad at software.

Re: Nvidia's RTX 5090 power connectors are melting

#193

Post by KeplerBoy »

baq wrote: post #171
KeplerBoy wrote: post #119

Earlier quoted context omitted.

If only we had connectors which could actually handle such currents. Maybe something along the lines of an XT90, but no Nvidia somehow wants to save a bit of space or weight on their huge brick of a card. I don't get it.

At these wattages just give it its own mains plug.

true. at this prices they might as well include a power brick and take responsibility of the current carrying path from the wall to the die.

Re: Nvidia's RTX 5090 power connectors are melting

#195

Post by eqvinox »

der8auer got his hands on the actual card, cable and PSU: https://www.youtube.com/watch?v=Ndmoi1s0ZaY (I'm assuming the content is identical to the German https://www.youtube.com/watch?v=puQ3ayJKWds - I haven't watched the English one)

Notable is that on the PSU connector side, 5 pins show heat damage. That means at minimum those 5 must have been carrying some current; i.e. only one of the 6 connections could have failed completely open.

On the PSU one of the ground pins was melted into the PSU connector, this should allow verifying if the plug was fully inserted by a lab disassembling and cross-sectioning it.

Re: Nvidia's RTX 5090 power connectors are melting

#196

Post by opencl »

lr1970 wrote: post #191
DannyBee wrote: post #97

Earlier quoted context omitted.

This is because they are trying to parallel like 50amps (it's 12 volt IIRC) over a few conductors to get to 600watts. If it becomes unbalanced due to any number of reasons, none of those individual cables can come close to handling it - they will all generate enough heat to melt lots of things. Conservatively, they'd have to be 8awg each to be able to handle the full load without melting if they ended up taking the f…

> If the voltage was higher (i believe 'low volt' classification tops out at 48v) Yep, 48V through sensitive parts of the body could be unpleasant but 24V is almost as safe as 12V. Why didn't they use 24V and 25A to achieve required 600W of power instead of 12V and 50A?

Because nobody makes 24V power supplies for computers, they'd have to convince the whole industry to agree on new PSU standards.

Re: Nvidia's RTX 5090 power connectors are melting

#197

Post by armada651 »

lr1970 wrote: post #191
DannyBee wrote: post #97

Earlier quoted context omitted.

This is because they are trying to parallel like 50amps (it's 12 volt IIRC) over a few conductors to get to 600watts. If it becomes unbalanced due to any number of reasons, none of those individual cables can come close to handling it - they will all generate enough heat to melt lots of things. Conservatively, they'd have to be 8awg each to be able to handle the full load without melting if they ended up taking the f…

> If the voltage was higher (i believe 'low volt' classification tops out at 48v) Yep, 48V through sensitive parts of the body could be unpleasant but 24V is almost as safe as 12V. Why didn't they use 24V and 25A to achieve required 600W of power instead of 12V and 50A?

Because no PC power supply has a 24V rail and even though there's a fancy new connector you can still use an adapter to get the old-fashioned plugs.

After all you don't want to limit your market to people who can afford to buy both your most expensive GPU and a new power supply. In the PC market backwards compatibility is king.

Re: Nvidia's RTX 5090 power connectors are melting

#198

Post by sangnoir »

engineer_22 wrote: post #123
Kirby64 wrote: post #112

Earlier quoted context omitted.

I’m aware we have 240V outlets. They are just not used in a place where you would put a PC. Until there is a shift in need (I.e., every normal user would need more than a 120V plug could handle), you won’t ever see 240V outlets in offices. I suspect it will never happen. In server areas and extremely specialized stuff? Yea, sure. But we’re talking desktop PCs here.

I envy my European friends' 240v electric kettles

British kettles draw so much power, the electric utility had to consider the additional power draw on the grid from synchronized tea-making during the commercial breaks of a popular soap opera, back when broadcast TV was king.

Re: Nvidia's RTX 5090 power connectors are melting

#199

Post by SketchySeaBeast »

hibikir wrote: post #157
SketchySeaBeast wrote: post #91

Earlier quoted context omitted.

Yeah, I expect my next card with be AMD. I'm happy with my 3080 for now, but the cards have nearly double in price in two generations and I'm not going to support that. I can't abide the prices nor the insane power draw. I'm OK with not having DLSS.

I agree with the prices, but you say you have a 3080, which has a higher max power draw than the 5080 or 4080. Power requirements actually went down

It's true, but to be fair, by the hardware the 5080 is really more of a 70 series cared in previous gens. I was just thinking of the insane top end of the 90 series.

Re: Nvidia's RTX 5090 power connectors are melting

#200

Post by karolist »

CommieBobDole wrote: post #90
buffet_overflow wrote: post #81

Earlier quoted context omitted.

Reminds me a bit of BMWs and their infamous and persistent coolant pump woes. The running joke in those circles is "replacing the entire cooling system" counts as "basic, regular maintenance". BMW makes a fantastic engine, then makes the water pump impeller out of plastic. For what feels like decades.

My E39 (which is a beacon of reliability for the brand) had a radiator neck made of a kind of plastic that becomes brittle with prolonged exposure to heat. It's a good thing there's no heat associated with the radiator. "Replace the entire radiator" was a ~70k mile maintenance task.

E39 beacon of reliability, is this sarcasm? I really can't tell
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