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A comment on Claude Code Daily Benchmarks for Degradation Tracking. Parent comment

Re:Claude Code Daily Benchmarks for Degradation Tracking by minimaltom on Thursday January 29, 2026 @01:06PM (#46813935)
Its not deterministic. Any individual floating point mul/add is deterministic, but in a GPU these are all happening in parallel and the accumulation is in the order they happen to complete.

When you add A then B then C, you get a different answer than C then A then B, because floating point, approximation error, subnormals etc.

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Re:Claude Code Daily Benchmarks for Degradation Tracking by bonoboTP on Thursday January 29, 2026 @05:29PM (#46817717)
It can be made deterministic. It's not trivial and can slow it down a bit (not much) but there are environment variables you can set to make your GPU computations bitwise reproducible. I have done this in training models with Pytorch.
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Re:Claude Code Daily Benchmarks for Degradation Tracking by minimaltom on Thursday January 29, 2026 @06:47PM (#46818589)
There are settings to make it reproducible but they incur a non-negligible drop in performance.

Unsurprising given they amount to explicit synchronization to make the order of operations deterministic.

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