Why are people using 3rd party cables after the 40 series disaster?
Because often it is the case that third party cables are of higher quality than stock cables, if you purchase from reputable vendors
Nvidia's RTX 5090 power connectors are melting
411–420 of 526 posts
Re: Nvidia's RTX 5090 power connectors are melting
#412Earlier 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…
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?
Because previous generation graphics didn't include ray/path tracing or DLSS technologies. They had baked in lighting and shaders that required much less compute to generate. Now that it does it requires more computing power that (we assume) Nvidia hasn't been able to solve with improved higher efficient computing power but simply by pushing more power through the card.
It's what Intel has been grappling with, their CPU's are drawing more and more wattage at the top end.
Re: Nvidia's RTX 5090 power connectors are melting
#413I've believed for a while now that GPUs are eventually going to get so big they'd need to be external to satisfy power and cooling requirements, and this is just more proof of that IMO.
There's a meme image somewhere out there of a GPU crudely photoshopped to look like a split-type AC condenser unit, i.e the kind you mount outside your house. It's pretty much how I picture GPUs will end up if things keep going the way they are.
Re: Nvidia's RTX 5090 power connectors are melting
#414Earlier quoted context omitted.
That sounds like someone buying a Lamborghini then trying to save money by fueling with regular gas.
But with gas the difference is at least somewhat legible to the layman. You see the octane rating and know you're getting something for that extra money. With cables they all look the same to the uninitiated, after all it connects doesn't it? So people are going to go for the cheaper option because they can't discern a reason not to.
The type of person who owns a 5090 must also be the type of person who knows about the 40 series and it's cable problems. Little timmy building his first PC wasn't camping outside of microcenter for a week just for a chance to spend $2000 on a video card
Re: Nvidia's RTX 5090 power connectors are melting
#415Earlier quoted context omitted.
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.
> 5080 is really more of a 70 series
Oft repeated, never explained.
The numbers don't really mean anything and never have. 5080 is faster than the 5070 is faster than the 5060. That's what the number means. The performance gap between tiers isn't and has never been constant.
Re: Nvidia's RTX 5090 power connectors are melting
#416Derbauer and Buildzoid on YouTube made nice informative videos on subject, and no it is not "simply a user error". So glad I went with 7900 XTX - should be all set for a couple of years.
> So glad I went with 7900 XTX - should be all set for a couple of years. Really depends on the use case. For gaming, normal office, smaller AI/ML or video-work, yeah, it's fine. But if you want the RTX 5090 for the VRAM, then the 24GB of the 7900 XTX won't be enough.
So funny because the only reason the 5090 has 32GB of RAM is because AMD put 24GB on the card they released against the 4080.
Re: Nvidia's RTX 5090 power connectors are melting
#417Earlier quoted context omitted.
> I envy my European friends' 240v electric kettles ... do you not have electric kettles in the US? Foolishly, I thought this was a standard kitchen appliance all over the world, I've even seen it in smaller cities in Peru.
We don't have a need for an exclusive water boiling device as we aren't obsessed with tea. Most people drink coffee and the heating element is already built into the coffee maker. Idk what else you'd use it for. The stove works fine for boiling water without needing a separate appliance.
They’re far faster than a stovetop most of the time, have auto shutoff so you can wander away for a minute or two or not pay attention to it and not boil off a lot of water, etc.
Many parts of the world, it’s a good idea to boil water before using it for drinking, brushing teeth, etc.
So it’s actually really convenient for many use cases besides tea or coffee.
Re: Nvidia's RTX 5090 power connectors are melting
#418Earlier quoted context omitted.
What power supply do you have that even has a 20A inlet? 20 amp breakers are common for outlets (especially in newer builds) but the outlets are still 15A outlets. And there is essentially no desktop power supply that exists that would exceed a 15A outlet currently.
> What power supply do you have that even has a 20A inlet? ATX PSUs usually have IEC 60320 C14 inlets. The IEC 60320 standard itself states that this inlet is only good for up to 10 Amps. UL is happy to ignore them and say that 15 Amps is okay. It wouldn't surprise me if someone else were happy to ignore that and say that 20 Amps is okay. Even still, swapping a C14 inlet for a C20 inlet (IEC max 16 Amps, UL max 20 Am…
Notably, 20 amps @ 120v is 2400 watts.
Re: Nvidia's RTX 5090 power connectors are melting
#419Earlier quoted context omitted.
Except when the "expected tolerance" is unreasonable. Even if the connectors and wires are to spec, the design leaves next to no margin for play. You need that margin to account for reality : Handling by casual end-users rather than trained professionals, the ambient temperature of the average room or office, dirt and grime that might get lodged and go unnoticed, wonky supply/draw of power, and more. Running 8.3A thr…
~23A had been measured going going through one of 6 wires/pins in this test: https://youtu.be/Ndmoi1s0ZaY?t=927 Standard requires these connectors to handle 9.5A per pin (9.5 A × 12 V × 6 pin = 684 W). A detailed explanation of this mess: https://www.youtube.com/watch?v=kb5YzMoVQyw
I'm curious, if there are any high level electrical engineers reading this please respond.
I wonder if that vertical (as far as the PCB goes) power connector will always ensure that this sort of imbalance will always occur. While we like to pretend that current is even in any given current plane that's not what happens. The impedance of the wires and copper is not perfectly ideal. This is why these connectors have equal number of grounds, so they have an ideal shortest path and balanced return current path. So I'm curious if electrically it's just impossible to have a vertical connector like that (on that shorts all the pins for 12V together instead of current balancing them) and have it balance current across the pins. The pins closest to the board should in theory have the greatest currents as they are the shortest path electrically. Based on the pictures that appears to be the case. It appears that the pins under the most stress are likely those with the lowest impedance.
Assuming my SWAG above is correct... I'm curious if this is affected by the per pin impedance on the PSU too. Where if certain folks are just unlucky get a situation where some pins in the connector have a significantly lower impedance than the rest.
If my second SWAG is plausible, my third and really bad SWAG is that removing the two ground pins nearest the PCB could actually "balance" the current better by forcing the current to use a slightly longer path for the power pins. But, my guess is this will just cause EMI issues. So please don't test this unless you're an EE and know what you're doing.
This is pure speculation on top of what Buildzoid, the posts above this have said, and what I've learned from Robert Feranec's videos. I'm in no way an electrical engineer, just a humble hobbyist and person that loves to learn.
Re: Nvidia's RTX 5090 power connectors are melting
#420People are letting their hatred of Nvidia blind them to what happened here, a customer upgraded from a 4090FE to 5090FE, they were using a 3rd party ASUS 12VHPWR cable and didn't realize the 5090FE actually uses 12V-2x6 not 12VHPWR, while the port is the same the pins are different lengths. End of the day PC power cabling is such a shambles with things that look standard but are not so you should only ever really use…
I mean unless you use the Nvidia adapter for the old fashioned 8 pins, then technically every cable is a third party cable. Or did Nvidia get into PSU sales?
Also 12V-2x6 only changes the female connector on the card, the male end on the cable is unchanged.