Gahow Wang
85b230455e
H7: Sweeping OVERLOAD_FACTOR (2.0/1.5/1.3/1.0) has no effect on GPU imbalance (~3.5-4x across all settings). Root cause: imbalance is from workload skew at session placement (turn 1), not from routing at turn 2+. H4 GPU profiling confirms: GPU balance improvement IS real (4.0x→2.0x), and it directly improves HEAVY_COLO TTFT by 10.5%. But RDMA-offloaded requests have bimodal transfer times (0.6s or 18-31s) that negate the routing benefit. Updated elastic_hypotheses.md with H7 results and next directions: higher load experiments where contention amplifies routing differences. Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>