An inefficient data pipeline causing bottlenecks is the most likely cause of prolonged training times and GPU underutilization in an optimized NVIDIA GPU cluster. If the data pipeline (e.g., I/O, preprocessing) cannot feed data to GPUs fast enough, GPUs idle, reducing utilization and extending training duration. NVIDIA's
"AI Infrastructure and Operations Fundamentals" and "Deep Learning Institute (DLI)" stress that data pipeline efficiency is a common bottleneck in GPU-accelerated training, detectable via tools like NVIDIA DCGM.
Insufficient power (A) would cause crashes, not underutilization. Inadequate cooling (C) leads to throttling, typically with high utilization. Outdated drivers (D) might degrade performance uniformly, not selectively.
NVIDIA's diagnostics point to data pipelines as the primary culprit here.