diff --git a/docs/RUNBOOK.md b/docs/RUNBOOK.md
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--- a/docs/RUNBOOK.md
+++ b/docs/RUNBOOK.md
@@ -348,4 +348,39 @@ Restart-Service act_runner
 # The prior snapshot is still in the template — jobs will use it immediately.
 ```
 
+---
+
+## 6. Windows host pre-migration baseline (reference for B7)
+
+Recorded 2026-05-17 — `Measure-CIBenchmark.ps1 × 4 iterations`, Python
+orchestrator post-Phase-A, Windows 11 + VMware Workstation Pro,
+template `WinBuild2025` / snapshot `BaseClean`.
+
+| Iter | Clone (s) | Start (s) | IP acquire (s) | WinRM (s) | Destroy (s) | Boot total (s) |
+|------|-----------|-----------|----------------|-----------|-------------|----------------|
+| 1    | 0.63      | 1.75      | 66.57          | 0.01      | 4.81        | 68.96          |
+| 2    | 0.63      | 1.89      | 20.21          | 0.01      | 6.39        | 22.74          |
+| 3    | 0.62      | 1.72      | 85.07          | 0.01      | 4.50        | 87.42          |
+| 4    | 0.61      | 1.72      | 60.97          | 0.01      | 4.20        | 63.31          |
+| **avg** | **0.62** | **1.77** | **58.20**     | **0.01**  | **4.98**    | **60.61**      |
+
+**Key finding**: IP-acquire phase dominates total time and is highly variable
+(20–85 s) due to VMware Tools guest IP detection latency. Clone/Start/WinRM
+are negligible and stable.
+
+**B7 comparison guidance** (tolerance ±20%):
+
+| Metric | Windows baseline | ±20% range |
+|--------|-----------------|------------|
+| Clone  | 0.62 s          | 0.50–0.74 s |
+| Start  | 1.77 s          | 1.42–2.12 s |
+| Destroy | 4.98 s         | 3.98–5.98 s |
+| Boot total (avg) | 60.6 s | 48.5–72.7 s |
+
+IP-acquire variance on Windows (σ ≈ 26 s) means boot-total comparison
+requires ≥10 samples on Linux to be meaningful. If Linux avg boot total
+exceeds 72.7 s, open an issue in `TODO.md` with per-phase breakdown before
+declaring B7 failed — check whether IP-acquire increased or non-IP phases
+regressed.
+