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Modder DallasGrave splits RTX 5090 power across two added 8-pin connectors
Reddit modder DallasGrave says his modified RTX 5090 ran 48 hours at 550W with its power cables never passing 40C. The result supports spreading current across more wires, though it comes from one card he measured himself.
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What happened
- The fix feeds an auxiliary dual 8-pin board from the card's power connections, spreading the load across three sets of cables.
- DallasGrave appears to be affiliated with Grave PC, a company that specializes in CPU and GPU cooling and compact system design.
- He said he is working on a "relatively affordable" service to convert existing cards, complete with a warranty.
- Tom's Hardware says it is unknown whether he designed the distributor himself or whether it contains capacitors and fuses.
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Why it matters
- contradiction DallasGrave pitches the board as a universal option across GPU brands, but Tom's Hardware says the resin-printed housing appears custom-made for his card, so fit on other boards is unproven.
- exposure Buyers of a converted card carry the risk that a promised warranty goes unhonored, given Tom's Hardware's report that PNY has been poor at honoring 12VHPWR claims involving third-party cables.
- constraint The fix needs wires soldered to the card's power rails, which Tom's Hardware calls invasive, so owners either do board-level work themselves or wait for a converter.
The stock connector has 16 pins, and four of them are sense pins. The other 12 split into six +12V and six ground connections [15]. On the 16AWG cable it typically uses, the design should in theory handle 600W [16]. At the test's 550W, the 12V side carries about 45.8A, or roughly 7.6A per +12V pin if all six share evenly [21][22]. Tom's Hardware attributes some melting to pins that make too little contact and heat up from the added resistance. It also calls uneven current distribution a frequent source of trouble [17].
A cool cable after the mod fits the idea that concentrated current causes the failures, though it does not separate those two faults. Splitting current across more wires lowers what each contact carries [4]. That helps whether the original problem was a bad pin or lopsided sharing [17]. Tom's Hardware reports that his card's 12VHPWR connector had been overheating before the fix [20]. Neither report includes a temperature for the stock setup at 550W to compare against [3].
I think he changed the right part. A higher-current header would leave the same six +12V wires in the cable [15]. He said as much: he could have replaced the header, but that does not fix the cable [11]. "12VHPWR is simply rated too high," he said [12]. He added that the connector never should have been approved beyond about 350W [13]. His stress test ran 200W past that figure, about 57 percent over it [23]. Tom's Hardware makes a related point about headroom. The older multi-8-pin setups rarely failed this way because their safety margins were higher [18].
The two reports place the solder work slightly differently. TechSpot describes a pickup PCB soldered to the contacts of the original 12VHPWR header [1]. Tom's Hardware describes extra connections soldered to the power rails on the card's PCB, routed to a distributor board that holds two female 8-pin sockets [5]. TechSpot rates it one of the cleanest fixes yet [8]. The comparison it draws is a TecLab mod from the summer that wired power straight to the GPU's PCB, which worked but was not pretty [7]. The temperature log is the modder's own measurement of a product he intends to sell [3][26].
The commercial plan so far comes from his Reddit replies. Asked whether PNY's warranty would cover the mod, he said: "We're a PNY partner. You'll be able to buy a PNY-specific card with a similar modification directly from us with a full warranty." [25] Tom's Hardware notes the mod is not currently on his website [14].
What to watch
- Grave PC listing the conversion service with a price and written warranty terms that say whether PNY or the converter stands behind the card.
- A statement from PNY on whether it honors warranties on partner-modified RTX 5090s, given its record on third-party cable claims.
- Independent temperature logs from the mod on other brands' RTX 5090 boards, testing the universal-fit claim against the custom-looking housing.