Gpt-oss training on A100 - OOM error

DhineshR
Fri, 21 Nov 2025 04:30:37 +0000

Though not set explicitly, the stack trace shows at some point the tensors are converted to fp32.

You could try increasing the batch size by 1 starting from 1 and find the breaking point.

You could also calculate size of activations for your batch_size, max_length, and precision of training. And, check if there is enough space left in the GPU for activations after allocating required amount of memory for fine-tuning.