This is a bug. A pretty alarming bug, especially given the recent spate of melting 12V-2x6 connectors, so it’s understandable that seeing a number so incredibly high would cause concern. However, it is just a bug. Your GeForce RTX 5080 is not running at 255°C.
Those of you with some knowledge of programming might already realise something fishy about that specific number, so let’s explain.
iCUE Says One of the Temperature Sensors in my 5080 is at 255 degrees. Why?
The reason for this half-funny, half-alarming number is that iCUE is looking for a specific sensor that is not present on the RTX 50 Series of GPUs. It will probably be displayed as “Temp #3” or something similar in iCUE.
For previous NVIDIA GPUs, this was reserved for the hotspot sensor, which was the way of reporting the highest temperature across the GPU, which was almost always the actual GPU die itself. Now that the 50 Series GPUs do not have such a sensor, iCUE gets confused as it can’t find any data, and comes back with 255 degrees. Most of the reports specifically mentioned a 5080, but this bug will be present on all 50 Series cards.
The main point to take away from this is that your GPU is not running that hot. Refer to the other sensors iCUE can get data from and you’ll see a more accurate temperature.
Basically, until this bug is fixed, you can just ignore it. Additionally, don’t bind any fan controls to this sensor, as the number its reporting is so high that it will likely max out your fans and make your PC noisier for no reason.
Now that your panic has been assuaged, let’s talk about why iCUE is reporting 255 degrees specifically, why not 0, or 999,999, or 41?
Why 255 Degrees Specifically?
We mentioned at the outset that any programmers out there will recognise 255 as a suspicious number. Those people were probably far less panicked as they saw the number for what it was – a pretty obvious bug.
Basically, iCUE reported this number because it wasn’t getting the data it expected, so it defaulted to 255, which is the highest number that can be represented in a single byte, or eight bits in binary.
So, stop worrying and enjoy being among the lucky few with a 50 Series GPU. This bug will be fixed soon, but in the meantime, use the other sensors to monitor your temperatures.