Melting GeForce RTX 4090 12VHPWR cables: What you need to know

Nvidia’s glorious GeForce RTX 4090 wowed reviewers and set a new bar for just how stupidly fast a graphics card could be. Unfortunately, the launch of the $1,600 GPU has been marred by multiple reports of melting 12VHPWR connectors used in the cards damaging both the connector and the GPUs at times.

The new 12VHPWR connector is a compact power connector that combines the capability of multiple older 6- and 8-pin connectors into one tiny plug. It was originally adopted with the GeForce RTX 3090 Ti Founders Edition and is now used in the GeForce RTX 4090 Founders Edition as well as custom versions of the RTX 4090 built by the likes of Asus, MSI, et cetera. The 12VHPWR connector will also be used in the impending GeForce RTX 4080 Founders Edition, slated to release on November 16.

As of Nov. 7, no less than 23 reports of melted connectors have surfaced in the Nvidia subreddit with another 5 unconfirmed cases.

With this fast-moving, confusing, and also very serious situation, PCWorld has decided to round up the facts you need to know to help separate fact from fiction. Nvidia officials have declined to comment while it investigates, but the latest development seem to point to bad 12VHPWR adapter cables. There’s also the possibility that not fully inserting the cable may cause increased resistance and enough heat to melt the connectors. We’ll update this story as new information is released.

• Sept. 10 Hassan Mujtaba of WCCFTech reports of an alert issued from PCI-SIG to members of a “thermal variance, which could result in safety issues under certain safety conditions.” The member alert advises vendors to “work closely with their connector vendors and exercise due diligence in using high-power connections”

• Sept. 14 The full email and additional details from the PCI-SIG are reported by Stephen Burke of Gamers Nexus and notes that “failures have been observed in certain cable routing conditions from PSUs and test boards that generate side load on the interface.” Burke said the report–apparently created by Nvidia–from PCI-SIG showed three different manufacturers have been tested with 10 sample assemblies with failures manifesting from 10 hours to 30 hours with melting. It’s worth pointing out that the internal report seems to refer to the connection on the PSU side—not the GPU side. In general, however, ATX 3.0 power supplies PCWorld have seen indicate the cables to be identical on both ends.

Brad Chacos/IDG

• Sept. 22 VideoCardz’s editor WhyCry reports that GPU maker Zotac’s guidance on the new 12VHPWR connector is rated for 30-insertion cycles which raises alarms as to the lifespan and durability of the new connector. VideoCardz later amends its report to say that while 30 cycles appears very low, many Molex connectors introduced over the last 20 years have had similar mating cycles.

• Oct. 24 The first report of a melted 12HPWR connector is posted on the Nvidia sub-reddit. The GPU appears to be a Gigabyte 4090 Gaming OC using an Nvidia-branded 12VHPWR adapter cable. Both Nvidia and Gigabyte reach out to the owner who reports a replacement card has been received. A second report of a melted dongle is received as well on that day with damage to the adapter cable and an Asus RTX 4090 TUF Gaming OC Edition occurring. The Reddit post immediately goes viral on the high-profile graphics card with many assuming the new connector to be at fault.

• Oct. 24 A few hours after the initial melting report on Reddit, renowned power supply reviewer and the principle behind PSU certification company Cybenetics, Aristeidis Bitziopoulos, attempts to replicate the melting 12VHPWR connector by subjecting it to 600 watt loads for more than 90 minutes. He is unable to damage the cable while seeing only a small thermal variance. It should be noted that the test used a native 12VHPWR cable on an ATX 3.0 power supply rather than Nvidia’s adapter. Bitziopoulos concludes the 12VHPWR connector doesn’t seem to be an issue in his testing.

• Oct. 24 Overclocker Buildzoid of Actually Hardware Overclocking, posts a video criticizing the new 12VHPWR connector noting that the new connector drastically reduces the number of pins and wires carrying power.

• Oct. 25. With failures now reported at three,  Nvidia officials tell the Verge’s Tom Warren that “we are investigating the reports” and are in contact with the owners of the impacted cards. 

• Oct. 25 Former HardOCP editor Kyle Bennett reports AMD’s upcoming RDNA3 GPUs will not use the 12VHWPR connector in its reference designs. Neither Bennett, nor his sources at AMD indicate when the design decision was made to skip 12VHPWR.
• Oct. 25 Showing what a distraction the 12VHPWR has become, AMD’s Scott Herkelman publicly confirms the new Radeon cards will skip 12VHPWR and receives responses such as “That is a HUGE relief, happy with that news.”

• Oct. 26 The official Reddit megathread listing showing documented failures now numbers five damaged 12VHWPR connectors.

• Oct. 26 Jason Langiven, aka JayzTwoCents, who has long been critical of the connector being “dangerous,” attempts to replicate the failure on a native 12VHWPR cable and is unable to induce a failure on the cable under heavy loads.

Brad Chacos/IDG

• Oct. 27 Igor Wallossek of IgorsLab.de conducts a tear down and failure test of a 12VHPWR power adapter and concludes that the issue doesn’t appear to be the 12VHPWR design itself nor the much-touted insertion cycle concern raised previously. Instead, Wallossek concludes it is the design of Nvidia’s adapter itself, which he describes as “inferior quality (and) can lead to failures and has already caused damage in single cases.” Wallossek said he believes bending and kinking of the adapter can cause weak solder joints and bridges to break and increase the resistance causing the melting.

• Oct. 28 Ronaldo Buassali of TecLab.net.br posts his own failure tests, including swinging a power supply using just the connector and subjecting to a stress test of 1,532—well beyond its rated sustained wattage of 600 watts.

• Oct. 30 Stephen Burke of Gamers Nexus attempts to replicate the melting failure by intentionally damaging a 12VHPWR adapter similar to what IgorsLab.de had reported and subjected it to a 99 percent load for 8 hours with no melting observed. Burke also notes that his five adapters all appear to be constructed the same—and yet differently than the adapter IgorsLab had. Burke said his five 12VHWPR adapters use wires labeled for 300 volts versus the 150 volts the adapter Wallossek had. Burke concludes that we just don’t know what the issue is, but it is a real problem on some adapters—but not all of them. He also mentions a theory being floated that the smaller connector may not easily seat as well as the larger traditional power connectors. He also points out that contrary to what many consumers believe, a native connector that plugs directly into a power supply may also fail the same way if the native cable is constructed the same as the failed adapters. Burke also asks owners of RTX 4090 cards to report which cable adapters they have.

• Oct. 30 With news that there appear to be different 12VHPWR adapters being provided, Stephen Burke of Gamer’s Nexus reports via Twitter that of the 130 emails he has received, 7 percent of owners report they have the 150V cabling that was used in IgorsLab’s adapter cable. Burke notes that while the cable marking may say 150V, that only means it uses the same apparent spec cables—and does not indicate they are may have the low-quality solder joints that IgorsLab found. Burke also notes that of the 130, “not many are burned.”

• Oct. 30 Andreas Schilling of Hardwareluxx.de conducts his own poll of forum members who have purchased RTX 4090 cards. He reports that 12 have a 4-pins-to-12VHPWR adapter marked “300V.” One has a 3-pins-to-12VHPWR marked “150V,” and two people have 4-pins-to-12VHPWR marked “150V.”

• Nov. 1 Ronaldo Buassali of TecLab.net.br posts a longer video of testing from the original live stream with additional explanations of how he tested the 12VHWPR. Unlike most of the testing so far, which used actual GeForce RTX 4090 cards, Buassali physically removes the 12VHWPR connector from the GPU and wires it up for stress testing. This lets Buassali push the connector assembly well past the 600 watts called for, including loads of 900 watts, 1,200 watts and 1,500 watts. Buassali’s conslusion? The 12VHPWR connector itself is “well sized, so much so that it supported much more than its specification.” However, Buassali concludes that even though the connector can handle more than it’s rated for, a poorly inserted connector that creates resistance could indeed be behind the melting of the connector. Buassali also doesn’t rule a batch of bad cables, but that implies a manufacturing issue, not a design problem.

• Nov. 2 Jon Gerow, director of R&D at Corsair and formerly of Jonnyguru.com, posts results from intentionally damaged 12VHPWR cable adapters under load and is unable to induce melting as well. Gerow was able to source multiple 12VHPWR adapter cables for destructive testing, and despite breaking off solder joints, he was unable to induce melting or a failure. He did note that some of the adapters weren’t constructed very well but even the worst of the batch passed stress testing without failing. Gerow concludes that some of the problems may have occurred when the owners didn’t fully seat the 12VHPWR adapter cables and also posts images of installed PCs where even a small gap of 1 mm could result in increased resistance.

• Nov. 3 AMD formally announces its RDNA3-based Radeon 7900XT and Radeon 7900XTX and proudly notes that it did not use 12VHPWR connections. However, the company points out that the general perception that it changed its designs only after the melting problems cropped up a few weeks ago is not correct. AMD made the decision to stay with conventional 8-pin power connectors more than a year ago.

• Nov. 4 A new post in the Nvidia subreddit, taken from a Facebook post of a Hong Kong-based RTX 4090 owner, is the first reported damaged 12VHPWR cable from a native cable plugged directly into a power supply. Previous to this report, all of the reported issues had only occurred in 12VHPWR adapter cables, not native cables. The following day, another person reports a melted connector using a native 12VHPWR cable from an ATX 3.0 power supply. This appears to dash hopes that a native plug would solve the problem.

• Nov 7 The number of confirmed failed connectors now numbers 23 on the Reddit megathread, with issues spread among many graphics card makers. Oddly, there are no Nvidia Founders Edition cards listed with failures. There are also five unconfirmed cases listed from other board makers as well.

• Nov. 7 VideoCardz editor WhyCry reports that a person on Reddit has been told his or her Gainward GeForce RTX 4090 will be delayed until the middle of November as it waits for replacement 12VHPWR adapter cables. The email, sent from Australian PC company Techfast to a customer, said “While investigations are still continuing and Nvidia has not released a public statement, Gainward has told us that cables shipped with their cards will (are) being replaced. As a result, they are holding shipping of all cards until this has taken place. We also understand this cable replacement will not be limited to Gainward alone.” PCWorld reached out to Techfast who confirmed the authenticity of the email.