Friday, February 28th 2025

12V-2x6 Adapter with Monitoring and Shunt Resistors Appears for NVIDIA's GPUs

A monitoring adapter prototype for NVIDIA's problematic 12VHPWR/12V-2x6 power connectors has surfaced in Asian markets, potentially offering RTX 5090 owners a stopgap solution amid ongoing concerns about thermal issues and power delivery weaknesses. The prototype features a circuit board with individually routed +12V lines through shunt resistors, enabling precise current measurement across each power line while maintaining ground and sense pin functionality. The adapter incorporates voltage monitoring capabilities and an apparent alarm function designed to trigger during overload conditions. A USB port is present on the board for user-accessible data output to a custom display. Notably, the current design iteration appears to omit temperature monitoring functionality, focusing exclusively on current distribution metrics.

These monitoring solutions merely detect rather than resolve the fundamental design issues reportedly affecting NVIDIA's high-end graphics cards. NVIDIA has maintained silence regarding the reported thermal issues and power supply inconsistencies affecting their flagship GeForce RTX 5090 cards despite growing user concerns about connector safety and performance stability. The emergence of third-party monitoring solutions proves the demand for greater transparency regarding power delivery characteristics, particularly for cards operating at extreme power limits. The RTX 5090, with its factory power limit of 600 W, represents the most power-hungry GPU, getting its massive power through a single 12V-2x6 connector interface.
Sources: BiliBili, via HardwareLuxx
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33 Comments on 12V-2x6 Adapter with Monitoring and Shunt Resistors Appears for NVIDIA's GPUs

#26
A Computer Guy
I'm not too surprised by this since the last major thread on this issue here. In fact I thought it would be an interesting idea if CableMod and Thermal Grizzly could reimplement their previous solutions by including the necessary circuitry to manage the power connector and protect the system. After all what's a $50 to $100 power adaptor but a drop in the bucket of cost when your paying $1,000+ for a GPU without proper safety measures? At this point there is a lot of money to be had among GPU owners who have to worry about this problem and would probably buy such a device to ensure their system doesn't go up in smoke, especially those that use custom cables.
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#27
mama
HairyLobsters12VHP is an ATX spec.
Well that fixes everything... :)
Posted on Reply
#28
AusWolf
VeseleilA community style solution for a premium product's deficiency.
Kind of like Linux vs Windows. Except that Linux actually works.
Posted on Reply
#29
OkieDan
N3utroIt's a good idea but it should automatically cut all power to the GPU if any overload is detected instead of just ringing an alarm
Would that not cause the card to attempt to draw 600W from slot, at least temporarily?
Posted on Reply
#30
Caring1
john_Or, we can hire someone to keep looking from the side panel while we are using our PC and in case he sees smoke to alarm us to quickly shut down the PC.
Well there's an idea, a 12V smoke detector, a built in sprinkler system, as well as automatic power cut off.
See Nvidia is creating jobs and opportunities for people.
Posted on Reply
#31
truerock
TheDeeGeeEveryone needs to switch to 4-spring, not just the cables that come with the GPU's.

It needs to become a new standard.
I agree. In fact, seeing how quickly 2-spring plugs came about, I won't be surprised if 4-spring is not the standard 12vHPWR cable included with a Corsair PSU in 2027.
Posted on Reply
#32
truerock
_roman_I just checked a few lines.

A Shunt resistor is not a fuse.
Monitoring is not a safety feature.

A fuse is a safety feature.

that stuff also needs temperature measurement probes.



Nope - Nope- Nope.

Really how do yo measure a current with a shunt - resistor? Maybe ohms law + shunt resistor + an analog / digital - converter in a microcontroller?

--

they should have added some circuitry on the psu side, not on the graphic card site, to hardware limit the current per wire. Which should be in the power supply unit in the first place. That connector is only specified for 600 Watts not 750 Watts what some overclockers use it for.
I have a Corsair HX1500i PSU. It has a USB-C port that feeds sensor data to the motherboard. I can use a Windows app to monitor the volts, amps and watts for each of the 3 PSU rails. It monitors temperature at 2 places. It does not monitor the individual plugs and definitely does not monitor the individual wires in each plug. I wonder how much it would cost to add that additional sensor data to a PSU.
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#33
_roman_
I hope you do not misunderstand me.

You power supply unit does not have any accuracy on the "measurements" like a true rms multimeter has. Therefore it is not a valid measurement. It's the same as with those cheap 8-15€ Schuko - 230V - WIFI measurement plugs. No accuracy given.

I would only trust a true rms clamp - multimeter in this regard or an oscilloscope with current probes.

www.corsair.com/us/en/p/psu/cp-9020215-na/hxi-series-fully-modular-atx-power-supply-cp-9020215-na#tab-techspecs

that's not much for tech specs.
assets.corsair.com/image/upload/corsairmedia/sys_master/productcontent/49_002614_AA_WW_HXi_Series_QSG_Web.pdf
cwsmgmt.corsair.com/documents/CE-000521AA%20HXi%20Series%20(2020)%20PSU.pdf

I did not expect to see even an accuracy in the first place.
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