alt Hacker NewsI'm not sure how you're arriving at "if you use the same seed with the same version of the software on the same hardware with the same drivers you get the same result is an exaggeration", it's wild that you're a teacher and you seemingly do not know this.
Order of operations affects the result in floating point, even moreso at lower precision. GPUs are massively parallel devices with many different sources of latency, so order of operations is not guaranteed for things like dot products, where many threads contribute to the result. Consequently, you can get non-deterministic outputs even though nothing else has changed.