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.
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.
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.
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.
I wouldn't be shocked if someone told me that Nvidia already sells more 48V parts than consumer 12V parts.
Look at the PCB of a 4090 GPU; you can find plenty of images of people removing the heatsink to fit water blocks. They literally have 24 separate transistors and inductors, all with thermal pads so they can be cooled by the heatsink.
The industry could change to 48v if they wanted to - although with ATX3.0 and the 16-pin 12VHPWR cable being so recent, I'd be surprised if they wanted to.
I guess the problem is not only designing the cards to run on the higher voltages but also getting AMD and Intel on board because otherwise no manufacturer is going to make the new power supplies.
It may be marine market specific, but several manufacturers limit to 36v for even high amperage motors because of it.
Obviously I=V/R will force this in the future though.
Going from 12V to 48 means you can get 600W through an 8-pin with a 190% safety factor, as opposed to melting your 12VHPWR.
12VHPWR is 8.4x20.8mm so it's got 7.7x the cross-sectional area but transmits only 2.5x the power. And 12VHPWR also has the substantial advantage that GPUs have fans and airflow aplenty.
So I can see why someone looking at the product might have thought the connector could reasonably be shrunk.
Of course, the trick USB-C uses is to deliver 5A at 48v, instead of 50A at 12v
Worth also mentioning that the same time the 12VHPWR connector was being market tested was during Ampere, the same generation where Nvidia doubled down on the industrial design of their 1st party cards.
Also there's zero devices out there that actually deliver or take 240W over USB-C. Texas Instruments literally only released the datasheets for a pivotal supporting IC within the last 6 months.
If you're saying that the connector doesn't have a 2x safety factor then I'd agree, sure.
But I can see how the connector passed through the design reviews, for the 40x0 era cards. The cables are thick enough. The pins seem adequate, especially assuming any GPU that's drawing maximum power will have its fans producing lots of airflow; plenty of connectors get a little warm. There's no risk of partial insertion, because the connector is keyed, and there's a plastic latch that engages with a click, and there's four extra sense pins. I can see how that would have seemed like a belt-and-braces approach.
Obviously after the first round of melted connectors they should have fixed things properly.
I'm just saying to me this seems like regular negligence, rather than gross negligence.
The 16-inch Framework laptop can take 240W power. For chargers, the Delta Electronics ADP-240KB is an option. Some Framework users have already tried the combination.
A few years ago there was a recall of OnePlus cables that were melting and catching fire, I had 2 of them and both melted.
But yes 240W/48V/5A is insane for a spec that was originally designed for 0.5W/5V/100mA. I suspect this is the limit for USB charging as anything over 48V is considered a shock hazard by UL and 5A is already at the very top of the 3-5A limit of 20AWG for fire safety.
The advantage of USB-C is the power negotiation, so getting the higher rating only on circuits that actually support it should de doable and relatively safe.
The OnePlus cable melting give me the same impression as when hair power cables melt: it's a solved problem, the onus is on the maker.
Users needing the 240W have a whole chain of specialized devices, so buying a premium cable is also not much of an issue.
In modern(last 4 years approximately) GPUs, physical wiring distance is starting to contribute substantially to latency.
The problem you will encounter with pcie gen5 risers is signal integrity.
It's about 75-90% the speed of light, but even that's too slow.
Modern hardware components are getting to latencies in single digit nanoseconds. Light travels about 30cms in a nanosecond, so extending a pcie port to a different box is going to have a measurable difference.
Also, these were vital to systems like the MacPro Trashcan that had 0 PCIe slots. This system was a horrible system, and everyone I know that had one reverted back to their latest 2012 cheese grater systems with the chassis.
There was another guy I know that was building his own 3D render rig for his own home experimental use when those render engines started using GPUs. He built a 220v system that he'd unplug the dryer to use. It had way more GPU cards than he had slots for by using PCIe splitters. Again, these were not used to draw realtime graphics to a screen. They were solely compute nodes for the renderer. He was running circles around the CPU only render farm nodes.
People think that the PCIe lanes are the limiting factor, but again, that's just for getting the GPUs data back to the screen. As compute nodes, you do not need full lanes to get the benefits. But for doubting Thomas types like you, I'm sure my anecdotal isn't worth much
You might think you're joking, but there are gamer cases with space for two PSUs, and motherboards which can control a secondary PSU (turning both PSUs on and off together). When using a computer built like that, you have two main plugs, and the second PSU (thus the second mains plug) is usually dedicated to the graphics card(s).
The second one was turned on with a paperclip, obviously.
Turns out graphics cards and hard drives are completely fine with receiving power but no data link. They just sit there (sometimes with fans at max speed by default!) until the rest of the PC comes online.
This would still have the disadvantage that the PWROK (grey) cable from the second PSU would not be monitored by the motherboard, leaving the machine prone to partial reset quirks during brown-outs. Normally a motherboard will shut down when PWROK is deasserted, and refuse to come out of reset until it returns.
PSUs can be removed from the PDB and replaced and reconnected to a source of power without having to shut down the machine or even remove the case lid. You don't even need to slide the machine out of the rack if you can get to the rear.
Example:
https://www.fspgb.co.uk/_files/ugd/ea9ce5_d90a79af31f84cd59d...
Edit: For example, in a 3+1 redundant setting, 3 PSUs would be active and contributing toward 1/3 of the total load current each; 1 PSU would be in cold standby, ready to take over if 1 of the others fails or is taken offline.
https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcQqLXew...
I'm not defending the shitty design here, but I'm all for always pushing the boundaries.
The problem isn't connectors, the problem (fundamentally) is to share electric connectivity between multiple conductors.
Sure, you can run 16A over 1.5 mm² wires, and 32A over 2.5 mm² (taken from [1], yes it's for 230V but that doesn't matter, the current is important not the voltage). And theoretically you could run 32A over 2x 1.5 mm² (you'd end up with 3 mm² cross section), but it's not allowed by code as when, for any reason, either of the two legs disconnects entirely or has increased resistance e.g. due to corrosion or a loose screw / wire nut (hence, please always use Wago style clamps - screws and wire nuts are not safe, even if torqued properly which most people don't), suddenly the other leg has to carry (much) more current than it's designed for and you risk anything from molten connectors to an outright fire. And that is what NVidia currently is running into, together with bad connections (e.g. due to dirt ingress).
The correct solution would be for the GPU to not tie together the incoming individual 12VHPWR pins on a single plane right at the connector input but to use MOSFETs and current/voltage sense to detect stuff like different current availability (at least it used to be the case with older GPUs that there were multiple ways to supply them with power and only, say, one of two connectors on the GPU being used) or overcurrents due to something going bad. But that adds complexity and, at least for the overcurrent protection, yet another microcontroller plus one ADC for each incoming power pin.
Alternatively each 12VHPWR pair could get its own (!) DC-DC converter down to 1V2 or whatever the GPU chip actually needs, but again that also needs a bunch of associated circuitry.
Another and even more annoying issue by the way is grounding - because all the electricity that comes in also wants to go back to the PSU and it can take any number of paths - the PCIe connector, the metal backplate, the 12VHPWR extra connector, via the shield of a DP cable that goes to a Thunderbolt adapter card's video input to that card, via the SLI connector to the other GPU and its ground...
Electricity is fun!
> Alternatively each 12VHPWR pair could get its own (!) DC-DC converter down to 1V2 or whatever the GPU chip actually needs, but again that also needs a bunch of associated circuitry.
So as you say, monitoring multiple inputs happened on the older xx90s, and most cards still do it. It's not hard.
Multiple DC-DC converters is something every GPU has. That's the only way to get enough current. So all you have to do is connect them to specific pins.
It still is because in the end you're dealing with dozens of amps on the "high" voltage side and hundreds of amps on the "low" (GPU chip) voltage side. The slightest fuck-up can and will have disastrous consequences.
GPUs these days are on the edge of physics when it comes to supplying them with power.
Doing the power conversion is hard.
Realizing that you already have several DC converters sharing the load, and deciding to power specific converters with specific pins, is comparatively easy. And the 3090 did it.
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?
We already have a new PSU standard, it's called ATX12VO and drops all lower voltages (5V, 3.3V), keeping only 12V. AFAIK, it's not seen wide adoption.
I would say it makes sense if you want to cut the PSU entirely, for racks of servers fed DC, but in that case it looks like 48V wins.
Your CPU steps down 12 volts to 1 volt and a bit. So does your GPU. If you see the big bank of coils next to your CPU on your motherboard, maybe with a heatsink on top, probably on the opposite side from your RAM, that's the section where the voltage gets converted down.
https://www.siemens.com/global/en/products/automation/power-...
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.
Servers with NVIDIA H200 GPUs (Supermicro ones for example) have power supplies that have 54 volt rail, since that gpu requires it. I can easily imagine a premium ATX (non-mandatory, optional) variant that has higher voltage rail for people with powerful GPUs. Additional cost shouldn't be an issue considering top level GPUs that would need such rail cost absurd money nowadays.
> Additional cost shouldn't be an issue considering top level GPUs that would need such rail cost absurd money nowadays.
Bold of you to assume that Nvidia would be willing to cut into its margin to provide an optional feature with no marketable benefit other than electrical safety.
It could probably be spinned into some performance pitch if you really want to.
Why would that be optional on a top of the line GPU that requires it? NVIDIA has nothing to do with it. I'm talking about defining an extended ATX standard, that covers PSUs, and it would be optional in the product lines of PSU manufacturers. The 12VHPWR connector support in PSUs is already a premium thing, they just didn't go far enough.
On the other hand, the voltages used inside a GPU are around 1V, and a higher input voltage introduces lower efficiency in the local conversion.
12V is only really used because historically it was available with relatively high power capacity in order to supply 12V motors in disk drives and fans. If power supplies were designed from the ground-up for power-hungry CPUs and GPUs, you could make an argument for higher voltage, but you could also make an argument for lower voltage. Or for the 12V, either because it's already a good compromise value, or because it's not worth going against the inertia of existing standards. FWIW there is a new standard for power supplies and it is 12V only with no lower or higher voltage outputs.
Since they went so far to create a new cable which wont be available on old PSU they would have easily extended that slightly and introduced an entirely new PSU class which has a new voltage also. But now they went the easy route and it failed which is even worse as they will have to redesign it now instead of it being safely done the first time.
It's not like that. It's a design where PSU only provides 12V to motherboard and motherboard provides the rest. Only location of those connectors change. It's called ATX12VO.
In modern PC almost nothing draws from 3v3 rail, not even RAM. I'm pretty sure nothing draws 3v3 directly from PSU at all today.
5v rail directly from PSU only used for SATA drives.
Anyway there are pros and cons to using 12V, or lower or higher, and anything except 12V would require a new PSU so it's a hard sell. But even without that detail, I have a feeling 12V is a reasonable choice anyway, not too low or high for conversion either in the PSU or in the GPU or other component.
In any case, at the end of the day sending 12V from the PSU to GPU is easy. The connector used here is bad, either by design or manufacturing quality, but surely the solution can be a better housing and/or sockets on the cable side connectors instead of a different voltage.
Cutting the 5090 down from 575w to 400w is a 10% perf decrease.
But yes, I do agree that TDPs for GPUs are getting ridiculous.
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.
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.
Other companies do make products with lower power draw — Apple in particular has some good stuff in this space for people who need it for AI and not gaming. And even in the gaming space, you have many options for good products — but people who apparently have money to burn want the best at any cost.
So the point being, nvidia is optimizing for gamers who are willing to throw top dollar at the best gear, regardless of power draw. But it’s a choice, and other manufacturers can make different tradeoffs.
Lack of electricity production is entirely a human choice at this point. There's no need to output carbon to make it happen.
1. People want their desktop computers to be fast. These are not made to be portable battery sippers. Moar powa!!!
2. People have a powerpoint at the wall to plug their appliances into.
Ergo, desktop computers will tend towards 2000w+ devices.
"Insane!" you may cry. But a look at the history of car manufacture suggests that the market will dictate the trend. And in similar fashion, you will be able to buy your overpowered beast of a machine, and idle it to do what you need day to day.
Still? It runs Baldur's Gate 3. Not smoothly, but it's playable. I don't have an M4 Pro Max Ultra Plus around to compare the apples to apples, but I'd expect both perf and perf per watt to be even better.
If one trillion dollar company can manage this, why not the other?
But other people will look at that and say "Not smooth = unplayable. If you can do so much with 100w or less, then lets dial that up to 2000w and make my eyes bleed!"
We're not the ones pushing the limits of the market it seems.
It's what Intel has been grappling with, their CPU's are drawing more and more wattage at the top end.
The problem is the 12V architecture, so the only way you can ramp power up is to increase amperage, and sending 50A over a single wire would probably require 8AWG. That's... really not reasonable for inside a PC case.
Then again, burning down your house is somewhat unreasonable too.
The NEC permits using conductors #1/0AWG or larger for parallel runs, it doesn’t forbid it entirely.
Within conduit, there is basically no other option. In free air there are options (750 mcm, etc).
Even if there were, you could not pay me to try to fish 750 mcm through conduit or bend it
Ford Focus Mk3 and Prius Prime 2024.
Yup. The door had weird failure cases that needed a recall.
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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.
But when Founders Edition cards made by NVidia are $2000 and the FE editions have no such mechanism, why would any AIB maker go above and beyond?
You just make your cards more expensive and it's difficult to tell consumers what the difference is exactly.
That said, it's the difference between "fairly unreliable" and "spectacularly unreliable".
A 530i Sport with a manual (!!!) popped up near me for a song but I just can’t justify 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.