Okay, so this Nvidia RTX 50-series hotspot sensor situation is a mess, a real mess. Brazilian repair specialist Paulo Gomes, along with Sidnelson, they’ve shown that the hotspot temperature sensor on these Blackwell GPUs, it’s there, it’s physically there, but Nvidia removed the API access for it. This means your standard tools, like GPU-Z or HWiNFO, they can’t read it. They just show you the average GPU temperature, and that’s not enough, not nearly enough.

The tool they used, it’s called MODS, Modular Diagnostic Software, and it’s an internal Nvidia tool. It’s for testing, for manufacturing, for RMA processes, not for us, the public. But copies are circulating, you know, in repair shops and on Discord servers. It needs a Linux boot environment, command line access, it’s not a simple Windows click.

Why does this matter? Well, Gomes showed a Gigabyte RTX 5070 Ti, it was sent in because of overheating issues. Windows monitoring tools, they reported an average GPU temperature of like 67 to 68 degrees Celsius, which sounds fine, right? But with MODS, the hotspot temperature, it was hitting 107 degrees Celsius.

That’s a massive difference, like 39 degrees Celsius. Nvidia’s thermal limit for the RTX 50-series is 107 degrees Celsius, and when it hits that, the GPU throttles, it reduces clock speeds, and performance drops. This specific card, the problem was poor thermal paste application, the paste was dry in the center, not making good contact. After reapplying the thermal paste, the hotspot dropped to around 100 degrees Celsius, and the card performed as it should.

So, if users had access to this hotspot data, they could diagnose these problems themselves. It’s a critical piece of diagnostic information, and Nvidia just hid it. The RTX 50 series, these are Blackwell architecture GPUs. They were announced at CES 2025, with the RTX 5070, 5080, and 5090 debuting in January 2025.

They use TSMC’s 4N process node. Nvidia says Blackwell is all about AI-driven rendering, neural shaders, and DLSS 4. The RTX 5090, it has 92 billion transistors and can do over 3,352 trillion AI operations per second. It’s supposed to be up to 2x faster than the RTX 4090.

And speaking of Nvidia, CEO Jensen Huang confirmed on July 13, 2026, that the Rubin Ultra architecture is still on track for next year, meaning 2027. Rubin Ultra is going to be big, like 576 GPU compute dies per rack. It’s expected to have 100 PFLOPS NVFP4 per GPU. Rubin itself, the predecessor, is scheduled for release in Q3 2026, using TSMC’s 3 nm process and HBM4 memory.

It’s a lot of power, a lot of heat, and that makes this hotspot sensor thing even more relevant, doesn’t it? I bought NVDA stock on July 10, 2023, at $42.10 a share. I’m holding until it hits $250, or if the Rubin Ultra launch gets delayed significantly, then I’ll re-evaluate. It was a good entry point back then, a really good entry point.

The average GPU temperature, it’s just a weighted average of hundreds of sensors across the die. The hotspot is the absolute maximum reading from the hottest point. A 30 degree Celsius difference between core and hotspot is considered normal. But when the hotspot hits 110 degrees Celsius, that’s usually when thermal throttling kicks in.

Nvidia’s limit for the 50-series is 107 degrees Celsius. So these cards are running right up against that limit, and without the hotspot data, users are blind. Why would they do that? What’s the point of hiding crucial diagnostic information from your customers?

It just creates more problems for everyone, for the users, for the repair shops, and ultimately, for Nvidia’s reputation. It’s a bad look.