During a 48-hour NeMo question-answering model burn-in test, GPU memory errors occur when processing large...

NVIDIA NeMo and large language model (LLM) training workloads are extremely demanding onHBM (High Bandwidth Memory). Out-of-Memory (OOM) errors often occur not because the total dataset is too large, but because memory fragmentation or sudden spikes in allocation (spikes during data shuffling or batch loading) exceed the available GPU memory. To mitigate this during intensive burn-in tests, engineers utilize theRMM (RAPIDS Memory Manager)library, which provides an asynchronous allocator. Enabling RMM asynchronous allocation allows the system to pre-allocate a pool of memory and manage it more efficiently than the standard CUDA allocator, reducing the overhead of constant allocations and deallocations. Furthermore, setting a specific blocksize (e.g., 1GB) for data loading ensures that the data ingestion pipeline reads data in manageable, deterministic chunks. This prevents the system from attempting to load massive files entirely into memory at once, which is the primary cause of OOMs in question-answering tasks involving large Parquet or JSON datasets. Switching to FP32 (Option B) would actually double the memory footprint and increase the likelihood of an OOM error.