Redditor builds an open-source tool to prevent RTX 5090 power connector failures, works like a charm

A PC enthusiast just built a free tool in his spare time that reportedly protects RTX 5090 owners better than anything the GPU industry has shipped so far. Interestingly, he did it by leaning on AI coding help, which may rub some people the wrong way.

Reddit user Khalid released "12VHPWR Guard," a small Windows application that reads per-pin current draw straight off the I2C bus on ASUS ROG Astral RTX 5080, RTX 5090, and ROG Matrix RTX 5090 cards.

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If any single pin pulls more than 9.5A for over 15 seconds, below ASUS's own 9.2A warning threshold, the tool force-closes background apps and shuts the system down. The current threshold and time window are both adjustable, and the app leans on HWiNFO's shared memory as a backup if it can't talk to the sensors directly.

That per-pin visibility is important because it's exactly what's been missing since NVIDIA dropped the shunt resistors that let older RTX 30 series cards detect an unbalanced connector. Every RTX 40 and RTX 50 series card treats all six 12V pins as one shared source, so if a handful of pins lose contact, the remaining ones can end up carrying way more current than they're rated for, and the GPU has no way to tell that's happening. That flaw traces back to the original RTX 4090 meltdown reports, and it's the common thread running through basically every 5090 connector story since.

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It's also part of the reason why the official fixes haven't held up well. ASUS's own $50 ROG Equalizer cable was marketed as a burn-proof solution with per-wire load balancing, and it still turned up with melted pins on Chiphell forums. ASRock's TempGuard, which is supposed to monitor connector temperature and cut power automatically, failed to trigger during a documented meltdown on a properly seated cable.

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Even Thermal Grizzly's WireView Pro II and MSI's GPU Safeguard haven't fully stopped the problem, since none of them can act on the actual current draw per pin the way Khalid's tool does.

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It's also interesting to note that Khalid says the tool was largely "vibe coded," meaning he leaned on an AI coding assistant to help stitch the logic together rather than writing everything from scratch. It's a good example of how accessible these tools have made building genuinely useful software, even for hardware safety monitoring that companies with entire engineering teams haven't nailed down.

Frequently Asked Questions

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Question #1

Which ASUS RTX 5080/5090 models are compatible with 12VHPWR Guard’s per-pin sensor monitoring?

12VHPWR Guard works with ASUS ROG Astral RTX 5080, ASUS ROG Astral RTX 5090, and ASUS ROG Matrix RTX 5090 cards. The article notes the tool is limited to a handful of premium ASUS models that expose per-pin sensors.

Answered

Question #2

What default current and time thresholds does 12VHPWR Guard use before shutting down the system?

12VHPWR Guard defaults to shutting the system if any single pin draws more than 9.5A for over 15 seconds. The current threshold and time window are both adjustable, per the primary article.

Answered

Question #3

How does 12VHPWR Guard behave if it can't read sensors directly from the GPU?

If 12VHPWR Guard cannot talk to the GPU sensors directly, the app falls back to HWiNFO's shared memory as a backup data source. It still enforces its protections , force-closing background apps and shutting the system down when a single pin exceeds the configured current/time threshold.

Answered

Question #4

How does Khalid’s tool differ from ASUS’s ROG Equalizer cable and ASRock’s TempGuard in preventing connector failures?

Khalid’s 12VHPWR Guard reads per-pin current directly from the card’s I2C sensors (with HWiNFO fallback) and force-closes apps then shuts the system down if any single pin exceeds a configurable current/time threshold, so it prevents failures by acting on actual per-pin overcurrent. ASUS’s ROG Equalizer is a hardware cable designed for per-wire load balancing and higher current capacity but has still shown melted pins in field reports. ASRock’s TempGuard monitors connector temperature and will cut power on overheating, but it failed to trigger during a documented meltdown, unlike Khalid’s current-based, per-pin approach.

Answered

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Right now, the tool only works with cards exposing per-pin sensors, limiting it to a handful of premium ASUS models. Still, if you're running a $2,000-plus RTX 5090, it's a free safety net already outperforming products people paid for.