Another 16-pin GPU power connector gets scorched, but this time it's not an RTX 5090 — User finds their Sapphire Nitro+ 9070 XT with scorched pins

How does the saying go? "Same s***t, different day."

I originally wanted a card that used the more aesthetically pleasing 12x6, but settled for what was available - my Gigabyte card uses no less than THREE 8 pin connectors. So, the only thing I have to worry about is melting thermal putty :LOL:

valthuer said:

During 2025, it has been “lol Nvidia and their melting connectors,” and now AMD is like hold my 12V-2x6.

When even a midrange AMD card starts roasting its power pins, maybe — just maybe — the issue isn’t green vs red, but that cursed 16-pin connector itself.

If AMD GPUs are starting to pull RTX-level fire hazards too… yeah, things are not looking great.

One important difference... Well, as I understand it and has been reported at least: AMD does not force AIBs to use the 12VHighFailure connector, like nVidia does. This is Sapphire's blunder for making the Nitro+ with it. It's THE reason why I did not buy it and instead got the Sapphire Pulse with regular 8pins. I think there's an AsRock model that also uses the 12VHighFailure connector. Stay away from them.

Also: the CPU 8Pin EPS can deliver up to 300W (nominal/average), so this design was absolutely* and completely unnecessary and, as pointed out by others, this is squarely on nVidia with some help from very ashamed Intel engineers. Legally, nVidia can't say the design is at fault, otherwise they'd open themselves to litigation and, at the same time, it would be a shame to drop a few pennies on people affected by this with only 60BN in the bank. Can you imagine spending thousands of shekles on this? It would debastate poor startup nVidia.

Regards.

Here is a repost of my Aug 22, 2025 comment on the article https://forums.tomshardware.com/threads/amd-zapped-with-16-pin-power-connector-melting-issue-for-the-first-time-%E2%80%94-radeon-rx-9070-xt-paired-with-sub-par-psu-gets-singed.3885168/ . This also address why we keep seeing mainly the 12V side pins get burns (by the sense pins). The return pins get helped by an unintentional ground loop that exists in the ATX power supply design, finding a return path through the motherboard PCIe power return conenctions.

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Without a doubt this is a design issue, coming from a power electronic engineer who designs high power and even aerospace power systems. I have been following this and have recognized several issues:

1. Hard paralleling connector pins/sockets is not a good idea unless there are some mitigation to force equal currents on both the 12V wires and the return wires. Despite people imparting their ideas on how simple this is, it actually isn't. Adding into the mix that the contact resistance is heavily affected by moisture and oxidation, it does not help that these GPUs and cables tend to be transported globally by ship, increasing the chance for heavy high oxidation buildup due to moisture. And this is made twice as likely by doubling up the connectors: one on the GPU and one on the PSU.

2. The high pin count connectors that have been chosen do not have enough derating per pin. Some of the Molex pins and sockets show derating to 5.5A per pin in this high of a pin count connector shell. This is despite what the standards group published in their specification page. It appears this is where the error started, with whoever was a part of that steering group. The heat will build highest in the center of the connector and as pins damage, the current will shed to the outside pins over time resulting in a row of damaged pins and melted nylon.

3. The cooling systems utilized in PC systems are not favorable for helping with cable cooling. Most notably is the use of aesthetic cable shrouds or webbing. There is large heat generation in the connector and headers, with not that much in the wires in a healthy design. The connectors are relying on heat conduction into the wiring and PCB to pull heat out. If the wires are covered with a shroud, the cooling effect from the wires is greatly diminished. Add in the aesthetics that the industry has made by including connectors on this cable for the PSU side, and it creates a significant problem: the market wants the aesthetics, but it is bad for the design.

4. There exists a large ground loop within the ATX PSU, motherboard, and the GPU system. This ground loop oddly enough helps keep the return wires from being damaged, as the return current can take an alternate path through the PCIe connector, into the motherboard, and back to the PSU through the ATX connector. This causes a noticeable reduction in return wire damage in the GPU cables, but it exposes the path through the motherboard to damage from unintended high current.

Here are some examples of the 12V side pins being damaged without any damage to the return wires. Note that this is not a scientific collection of data, just my observations that most of the pictures shared have this common failure mode. But there are also many other pictures showing both 12V and return pins damaged, indicating the ease of a manufacturing error stacking up and causing failures. Below, the pictures show that the 12V pins are damaged, and they are right next to the smaller 4 signal pins:


Notice on all of these the 12V wires are only damaged (by the 4 pin signal connectors):

https://cdn.mos.cms.futurecdn.net/uAVyHuRtHVs8iefTFsupNH-650-80.jpg.webp


https://cdn.mos.cms.futurecdn.net/QTebHt45YSd8Nq8oXu54q8-650-80.png.webp

@valthuer (I think this was yours)
https://i.postimg.cc/R0ttdFgj/IMG-8616.jpg


https://cdn.mos.cms.futurecdn.net/ZdZ6MHbJv6MGnR3U9YyKLS-650-80.jpg.webp


https://cdn.mos.cms.futurecdn.net/4VQ6en2uzoE2Nxk47ungiM-650-80.jpg.webp


In the meantime, here are some suggestions for users to reduce failures (no guarantees though):

1. Do not use cabling that has a wiring loom wrapped around it, which acts as to reduce and constrict the airflow. The datasheets are expecting decent wire cooling to draw heat away from the connector housing, i.e., no "pretty" nylon shroud covering the wiring to allow for reasonable convection cooling of the wire. If this loom exists, remove it and allow the wire insulation to convection cool better. The wiring looms should require yet another current derating if you want to use them.

2. The wire is expected to act as a heatsink for the connector pins and sockets. This is how connector systems are designed by intent. Again this is simple physics. The pin and socket contact points are tiny and much smaller than the wire cross-sectional area. For this reason, suppliers should find a way to use larger wire than is presently being used.

3. Since the pin and socket contact points have gone through oxidation and corrosion before you even install them, you should plug and unplug them several time to knock this oxidation off. Don't get excessive with it because you don't want to create fretting failure by scrapping off too much tin plating. About 3-5 time is great. Make sure the last pass is seated well. Do all of this for both ends (PSU as well).

4. You want to get the heat out of the cabling ends. So mount a fan by the GPU connector if you can, as well as at the PSU connector. The resistance imbalance can occur at both ends!

I hope these suggestions help people while the industry addresses these shortcomings.