8 ms·

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 c

by Havoc 2y ago

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.

buffet_overflow 2y ago
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.
- CommieBobDole 2y ago
  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.
  - karolist 2y ago
    E39 beacon of reliability, is this sarcasm? I really can't tell
    - CommieBobDole 2y ago
      It's not, actually - the E39s are incredibly reliable compared to more recent models. I drove mine for 20 years. That said, it's the difference between "fairly unreliable" and "spectacularly unreliable".
      - CobaltFire 2y ago
        I miss mine enough I’ve been debating on buying another. A 530i Sport with a manual (!!!) popped up near me for a song but I just can’t justify it.
  - CobaltFire 2y ago
    Yup, mine blew apart in traffic on H1 (Oahu) at 35MPH when the car (530i) was ~3 years old. I think it had maybe 35k miles on it. Dealer offered to allow me to pay extra for an all aluminum since that’s what they recommended but the factory wouldn’t cover.
- isatty 2y ago
  I have the B58 which is fantastic and does come with an all metal, mechanical water pump which I thought would be a pleasant break, but my gasket still failed. BMW and water pumps, classic.
dragontamer 2y ago
Both of my previous cars had door recalls. Ford Focus Mk3 and Prius Prime 2024. Yup. The door had weird failure cases that needed a recall. -------- Connectors and cables is damn near Masters level in knowledge and application. Its a rarely studied and often ignored piece of engineering. The more you learn about them, the crazier it gets. That being said, this news that the 4090 and 5090 are using but one shunt resistor for all 6 power pins is horrifying to me. I'm not Power Engineer but it looks horrifyingly wrong to my napkin math. People underestimate the problems of physical design or the design effort needed to make good designs.
- gloxkiqcza 2y ago
  A bit off topic, but this is something HN might enjoy. It’s a video by a mechanical engineer that worked for Tesla, Apple and a NASCAR team about Tesla door handles over time. https://youtu.be/Bea4FS-zDzc https://youtu.be/Bea4FS-zDzc
  - wing-_-nuts 2y ago
    I see content like this, and it inspires me for what I want my retirement to be like. Just some crazy old eccentric puttering about, tinkering in his workshop. I want my back yard to look like a solar punk world's fair.
- BonoboIO 2y ago
  Yeah, but we also have reliable mature connectors for decades, and they try to make new connectors and it’s not rocket science to transfer that kind of load.
- immibis 2y ago
  A card that draws 600 watts likely already has more than 6 phases of power conversion, so it could put a separate phase on each pin, and one more on the PCIe slot power, and then guarantee load balancing as well as being able to detect any single broken connection.
  - dragontamer 2y ago
DannyBee 2y ago
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 full load onto a single conductor. That's the crappy part about low voltages. If the voltage was higher (i believe 'low volt' classification tops out at 48v), it'd be more dangerous to deal with in some aspects, but it'd be easier to have small cables that won't melt.
- ta988 2y ago
  But you would then need to bring it down to the low voltages required by the chips and that would greatly increased cost, volume, weight, electrical noise and heat of the device.
  - DannyBee 2y ago
    Yes. I'm not suggesting they increase the voltage, as i said, there are lots of tradeoffs. But i'll also say - outside of heat, all of the things you listed are not safety concerns (obviously, electrical noise can be if it's truly bad enough, but let's put that one mostly aside). Having a small, cost efficient, low weight device that has no electrical noise is still not safe if it starts fires.
  - mpreda 2y ago
    The voltage step-down is already in place, from 12V to whatever 1V or 0.8V is needed. Doing the same thing starting from 48V instead of 12V does not change anything fundamentally, I guess.
    - ta988 2y ago
      It changes a lot. You are switching at different frequencies and although the currents are smaller, there is an increased cost if you want to do it efficiently and not have too many losses. But anyway for consumer products this is unlikely to happen because it would force users to get new power supplies which would reduce their sales quite drastically at least for the first one they make like that. The solution would maybe be to make a low volume 48V card and slowly move people over it showing them it is better? Anyway this is clearly not a case of "just use X" where X is 48V. It is much more subtle than that.
threeducks 2y ago
It boggles the mind how a $10 space heater has better overheating protection than this $4000 space heater.
- 0x457 2y ago
  To be fair, $10 space heater main purpose is to get hot, so makes sense there is protection from getting too hot.
bastardoperator 2y ago
My 4090 connector melted too
deleted 2y ago
[deleted]
roland35 2y ago
Cables are hard! Back when I did EE work we tried to avoid cables as much as possible because they cause all sorts of annoyances
Denvercoder9 2y ago
It's not an engineering problem, it's a political problem. If you present this problem to any power engineer at Nvidia, they'd probably say something akin to "yeah, delivering 600W at 12V over a 12-prong connector is insane, up the voltage". The issue is that 12V has been the standard voltage for ages, and if you want to sell a product that requires a higher voltage, you first need to get the industry to produce PSUs that deliver a higher voltage.

by Havoc 2y ago

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.

buffet_overflow 2y ago

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.

CommieBobDole 2y ago
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.
- karolist 2y ago
  E39 beacon of reliability, is this sarcasm? I really can't tell
  - CommieBobDole 2y ago
    It's not, actually - the E39s are incredibly reliable compared to more recent models. I drove mine for 20 years. That said, it's the difference between "fairly unreliable" and "spectacularly unreliable".
    - CobaltFire 2y ago
      I miss mine enough I’ve been debating on buying another. A 530i Sport with a manual (!!!) popped up near me for a song but I just can’t justify it.
- CobaltFire 2y ago
  Yup, mine blew apart in traffic on H1 (Oahu) at 35MPH when the car (530i) was ~3 years old. I think it had maybe 35k miles on it. Dealer offered to allow me to pay extra for an all aluminum since that’s what they recommended but the factory wouldn’t cover.
isatty 2y ago
I have the B58 which is fantastic and does come with an all metal, mechanical water pump which I thought would be a pleasant break, but my gasket still failed. BMW and water pumps, classic.

dragontamer 2y ago

Both of my previous cars had door recalls. Ford Focus Mk3 and Prius Prime 2024. Yup. The door had weird failure cases that needed a recall. -------- Connectors and cables is damn near Masters level in knowledge and application. Its a rarely studied and often ignored piece of engineering. The more you learn about them, the crazier it gets. That being said, this news that the 4090 and 5090 are using but one shunt resistor for all 6 power pins is horrifying to me. I'm not Power Engineer but it looks horrifyingly wrong to my napkin math. People underestimate the problems of physical design or the design effort needed to make good designs.

gloxkiqcza 2y ago
A bit off topic, but this is something HN might enjoy. It’s a video by a mechanical engineer that worked for Tesla, Apple and a NASCAR team about Tesla door handles over time. https://youtu.be/Bea4FS-zDzc https://youtu.be/Bea4FS-zDzc
- wing-_-nuts 2y ago
  I see content like this, and it inspires me for what I want my retirement to be like. Just some crazy old eccentric puttering about, tinkering in his workshop. I want my back yard to look like a solar punk world's fair.
BonoboIO 2y ago
Yeah, but we also have reliable mature connectors for decades, and they try to make new connectors and it’s not rocket science to transfer that kind of load.
immibis 2y ago
A card that draws 600 watts likely already has more than 6 phases of power conversion, so it could put a separate phase on each pin, and one more on the PCIe slot power, and then guarantee load balancing as well as being able to detect any single broken connection.
- dragontamer 2y ago

DannyBee 2y ago

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 full load onto a single conductor. That's the crappy part about low voltages. If the voltage was higher (i believe 'low volt' classification tops out at 48v), it'd be more dangerous to deal with in some aspects, but it'd be easier to have small cables that won't melt.

ta988 2y ago
But you would then need to bring it down to the low voltages required by the chips and that would greatly increased cost, volume, weight, electrical noise and heat of the device.
- DannyBee 2y ago
  Yes. I'm not suggesting they increase the voltage, as i said, there are lots of tradeoffs. But i'll also say - outside of heat, all of the things you listed are not safety concerns (obviously, electrical noise can be if it's truly bad enough, but let's put that one mostly aside). Having a small, cost efficient, low weight device that has no electrical noise is still not safe if it starts fires.
- mpreda 2y ago
  The voltage step-down is already in place, from 12V to whatever 1V or 0.8V is needed. Doing the same thing starting from 48V instead of 12V does not change anything fundamentally, I guess.
  - ta988 2y ago
    It changes a lot. You are switching at different frequencies and although the currents are smaller, there is an increased cost if you want to do it efficiently and not have too many losses. But anyway for consumer products this is unlikely to happen because it would force users to get new power supplies which would reduce their sales quite drastically at least for the first one they make like that. The solution would maybe be to make a low volume 48V card and slowly move people over it showing them it is better? Anyway this is clearly not a case of "just use X" where X is 48V. It is much more subtle than that.

threeducks 2y ago

It boggles the mind how a $10 space heater has better overheating protection than this $4000 space heater.

0x457 2y ago
To be fair, $10 space heater main purpose is to get hot, so makes sense there is protection from getting too hot.

bastardoperator 2y ago

My 4090 connector melted too

deleted 2y ago

[deleted]

roland35 2y ago

Cables are hard! Back when I did EE work we tried to avoid cables as much as possible because they cause all sorts of annoyances

Denvercoder9 2y ago

It's not an engineering problem, it's a political problem. If you present this problem to any power engineer at Nvidia, they'd probably say something akin to "yeah, delivering 600W at 12V over a 12-prong connector is insane, up the voltage". The issue is that 12V has been the standard voltage for ages, and if you want to sell a product that requires a higher voltage, you first need to get the industry to produce PSUs that deliver a higher voltage.