so, if their experiment was designed such that reproduction is inherently difficult, they should have designed it in a better way, and they should've used a toolset that wouldn't run into that problem.
a non-reproducible experiment isn't necessarily completely without value, but it's a thing that everyone should look askance at till it proves its worth.
(apologies if my comments don't apply to this experiment and if it is reproducible -- i didn't have time to read through the OP, but i thought this reply was still a worthwhile response to its specific parent comment)
That being said the paper in question doesn't seem to reference open source code anyway so I guess my point was kind of moot, apologies.
There are specific CUDA operations which are not guaranteed to be reproducible though, as well as some CuDNN operations which are non-determanistic without performance sacrifice, and this does cause real problems.
See https://pytorch.org/docs/stable/notes/randomness.html for some reasonable docs on this.
Some operations split and join data in non-deterministic ways (especially the order of operations, leading to different floating point rounding). If you shard across multiple machines, weight accumulation order will depend on network latency for example.
Also, GPU's aren't anywhere near as reliable as CPU's when it comes to being able to run for hours without any random bit flips/errors.
Ah, of course! A very timely reminder, thanks!
> GPU's aren't anywhere near as reliable as CPU's when it comes to being able to run for hours without any random bit flips/errors.
Now that's worrying. A bit flip can't be expected to be skewed towards any particular bit within a float, so it could easily happen in the exponent, skewing a single value by orders of magnitude one way or the other. Combine that with the rest of your 'good' results and yuck. That's very concerning. Thanks for the warning.
Actually, I think they are - for example, the exponent path through an adder/multiplier is typically shorter, so when operated close to clock speed limits, the exponent is more likley to be correct.
(I've not actually verified the above on real hardware)