Estimate fan duty from observed RPM maxima

- NvidiaPowerBenchResult gains ServerPower *BenchmarkServerPower
- RunNvidiaPowerBench samples IPMI idle before Phase 1 and loaded via
  background goroutine throughout Phase 2 ramp
- renderPowerBenchReport: new "Server vs GPU Power Comparison" table
  with ratio annotation (✓ match / ⚠ minor / ✗ over-report)
- renderPowerBenchSummary: server_idle_w, server_loaded_w, server_delta_w,
  server_reporting_ratio keys

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

audit/internal/platform/benchmark.go

@@ -94,9 +94,13 @@ var (
 )
 
 // benchmarkPrecisionPhases lists the precision categories run as individual
-// steady-state windows before the combined steady pass.  Order is from lowest
+// steady-state windows before the combined steady pass. Order is from lowest
 // to highest power draw so thermal ramp-up is gradual.
-var benchmarkPrecisionPhases = []string{"int8", "fp8", "fp16", "fp32", "fp64", "fp4"}
+//
+// fp64 and fp4 are intentionally disabled for now: both are currently unstable
+// on the target fleet and can abort the mixed steady stage after the earlier
+// phases already collected useful telemetry.
+var benchmarkPrecisionPhases = []string{"int8", "fp8", "fp16", "fp32"}
 
 func computeCapabilityCode(raw string) int {
 	raw = strings.TrimSpace(raw)
@@ -124,6 +128,15 @@ func benchmarkSupportedPrecisions(computeCapability string) []string {
 	return out
 }
 
+func benchmarkPrecisionEnabled(category string) bool {
+	switch category {
+	case "int8", "fp8", "fp16", "fp16_bf16", "fp32", "fp32_tf32":
+		return true
+	default:
+		return false
+	}
+}
+
 func buildBenchmarkSteadyPlan(spec benchmarkProfileSpec, precisions []string, metricStage func(string) string) (planLabels []string, planPhases []benchmarkPlannedPhase, basePhaseSec int, mixedPhaseSec int) {
 	if len(precisions) == 0 {
 		precisions = append([]string(nil), benchmarkPrecisionPhases...)
@@ -514,6 +527,7 @@ func (s *System) RunNvidiaBenchmark(ctx context.Context, baseDir string, opts Nv
 				appendBenchmarkMetrics(&metricRows, cooldownRows, fmt.Sprintf("gpu-%d-cooldown", idx), &metricTimelineSec, float64(spec.CooldownSec))
 			}
 
+			applyBenchmarkSteadyFallback(&gpuResult)
 			gpuResult.Scores = scoreBenchmarkGPUResult(gpuResult)
 			gpuResult.DegradationReasons = detectBenchmarkDegradationReasons(gpuResult, result.Normalization.Status)
 			if anomaly := detectPowerAnomaly(metricRows, idx); anomaly != "" {
@@ -1108,6 +1122,7 @@ type benchmarkCoolingSample struct {
 	AvgFanRPM             float64
 	AvgFanDutyCyclePct    float64
 	FanDutyCycleAvailable bool
+	FanDutyCycleEstimated bool
 }
 
 func sampleBenchmarkTelemetry(gpuIndices []int) ([]GPUMetricRow, error) {
@@ -1120,6 +1135,7 @@ func sampleBenchmarkTelemetry(gpuIndices []int) ([]GPUMetricRow, error) {
 		samples[i].FanAvgRPM = fanSample.AvgFanRPM
 		samples[i].FanDutyCyclePct = fanSample.AvgFanDutyCyclePct
 		samples[i].FanDutyCycleAvailable = fanSample.FanDutyCycleAvailable
+		samples[i].FanDutyCycleEstimated = fanSample.FanDutyCycleEstimated
 	}
 	return samples, nil
 }
@@ -1127,11 +1143,12 @@ func sampleBenchmarkTelemetry(gpuIndices []int) ([]GPUMetricRow, error) {
 func sampleBenchmarkCoolingSample() benchmarkCoolingSample {
 	fans, _ := sampleFanSpeeds()
 	avgRPM, _, _ := fanRPMStats(fans)
-	dutyPct, dutyAvailable := sampleFanDutyCyclePct()
+	dutyPct, dutyAvailable, dutyEstimated := sampleFanDutyCyclePctFromFans(fans)
 	return benchmarkCoolingSample{
 		AvgFanRPM:             avgRPM,
 		AvgFanDutyCyclePct:    dutyPct,
 		FanDutyCycleAvailable: dutyAvailable,
+		FanDutyCycleEstimated: dutyEstimated,
 	}
 }
 
@@ -1373,44 +1390,91 @@ func summarizeBenchmarkCooling(rows []GPUMetricRow) *BenchmarkCoolingSummary {
 	}
 	var rpmValues []float64
 	var dutyValues []float64
+	var dutyEstimated bool
 	for _, row := range rows {
 		if row.FanAvgRPM > 0 {
 			rpmValues = append(rpmValues, row.FanAvgRPM)
 		}
 		if row.FanDutyCycleAvailable {
 			dutyValues = append(dutyValues, row.FanDutyCyclePct)
+			if row.FanDutyCycleEstimated {
+				dutyEstimated = true
+			}
 		}
 	}
 	if len(rpmValues) == 0 && len(dutyValues) == 0 {
 		return nil
 	}
 	summary := &BenchmarkCoolingSummary{
-		Available: true,
-		AvgFanRPM: benchmarkMean(rpmValues),
+		Available:             true,
+		AvgFanRPM:             benchmarkMean(rpmValues),
+		FanDutyCycleEstimated: dutyEstimated,
 	}
 	if len(dutyValues) > 0 {
 		summary.FanDutyCycleAvailable = true
 		summary.AvgFanDutyCyclePct = benchmarkMean(dutyValues)
 		summary.P95FanDutyCyclePct = benchmarkPercentile(dutyValues, 95)
+		if summary.FanDutyCycleEstimated {
+			summary.Notes = append(summary.Notes, "fan duty cycle is estimated from the highest fan RPM observed since boot; treat it as an approximation, not a direct PWM reading")
+		}
 	} else {
 		summary.Notes = append(summary.Notes, "fan duty cycle unavailable on this host; RPM-only fan telemetry was collected")
 	}
 	return summary
 }
 
+func benchmarkTelemetryAvailable(summary BenchmarkTelemetrySummary) bool {
+	return summary.Samples > 0 || summary.DurationSec > 0
+}
+
+func benchmarkPrecisionSteadyFallback(phases []BenchmarkPrecisionSteadyPhase) (BenchmarkTelemetrySummary, string, bool) {
+	var (
+		best      BenchmarkTelemetrySummary
+		bestLabel string
+		found     bool
+	)
+	for _, phase := range phases {
+		if !benchmarkTelemetryAvailable(phase.Steady) {
+			continue
+		}
+		if !found ||
+			phase.Steady.DurationSec > best.DurationSec ||
+			(phase.Steady.DurationSec == best.DurationSec && phase.Steady.P95PowerW > best.P95PowerW) {
+			best = phase.Steady
+			bestLabel = phase.Precision
+			found = true
+		}
+	}
+	return best, bestLabel, found
+}
+
+func applyBenchmarkSteadyFallback(gpu *BenchmarkGPUResult) {
+	if gpu == nil || benchmarkTelemetryAvailable(gpu.Steady) {
+		return
+	}
+	if fallback, label, ok := benchmarkPrecisionSteadyFallback(gpu.PrecisionSteady); ok {
+		gpu.Steady = fallback
+		gpu.Notes = append(gpu.Notes,
+			fmt.Sprintf("mixed steady telemetry unavailable; reporting steady-state fallback from %s precision phase", label))
+	}
+}
+
 func scoreBenchmarkGPUResult(gpu BenchmarkGPUResult) BenchmarkScorecard {
 	score := BenchmarkScorecard{}
 
 	// SyntheticScore: sum of fp32-equivalent TOPS from per-precision phases.
 	// Each precision ran alone with full GPU dedicated — peak capability.
 	for _, p := range gpu.PrecisionSteady {
+		if !benchmarkPrecisionEnabled(p.Precision) {
+			continue
+		}
 		score.SyntheticScore += p.WeightedTeraOpsPerSec
 	}
 
 	// MixedScore: sum of fp32-equivalent TOPS from the combined phase.
 	// All precisions compete simultaneously — closer to real inference workloads.
 	for _, p := range gpu.PrecisionResults {
-		if p.Supported {
+		if p.Supported && benchmarkPrecisionEnabled(p.Category) {
 			score.MixedScore += p.WeightedTeraOpsPerSec
 		}
 	}
@@ -1441,10 +1505,17 @@ func scoreBenchmarkGPUResult(gpu BenchmarkGPUResult) BenchmarkScorecard {
 	// so CV reflects genuine power regulation, not workload switching).
 	if len(gpu.PrecisionSteady) > 0 {
 		var sum float64
+		var count int
 		for _, p := range gpu.PrecisionSteady {
+			if !benchmarkPrecisionEnabled(p.Precision) {
+				continue
+			}
 			sum += clampScore(100 - p.Steady.PowerCVPct*3)
+			count++
+		}
+		if count > 0 {
+			score.PowerSustainScore = sum / float64(count)
 		}
-		score.PowerSustainScore = sum / float64(len(gpu.PrecisionSteady))
 	} else if gpu.Steady.PowerCVPct > 0 {
 		score.PowerSustainScore = clampScore(100 - gpu.Steady.PowerCVPct*3)
 	}
@@ -2512,6 +2583,7 @@ func runNvidiaBenchmarkParallel(
 	// Score and finalize each GPU.
 	for _, idx := range selected {
 		r := gpuResults[idx]
+		applyBenchmarkSteadyFallback(r)
 		r.Scores = scoreBenchmarkGPUResult(*r)
 		r.DegradationReasons = detectBenchmarkDegradationReasons(*r, result.Normalization.Status)
 		pr := parseResults[idx]
@@ -2694,18 +2766,21 @@ func summarizeCPULoad(samples []float64) *BenchmarkCPULoad {
 	return cl
 }
 
-// runBenchmarkPowerCalibration runs targeted_power per GPU and actively watches
-// throttle counters. If a GPU starts throttling, the current targeted_power run
-// is canceled immediately, the power limit is reduced, and a fresh full cycle
-// is started again from the beginning. The selected reduced power limit stays
-// active for the main benchmark and is restored by the caller afterwards.
+// runBenchmarkPowerCalibration runs targeted_power for the supplied GPU set and
+// actively watches throttle counters. seedLimits, when provided, are treated as
+// the starting point for this calibration pass rather than as immutable fixed
+// limits. This matters during cumulative ramp-up: once an additional GPU is
+// introduced, every already-active GPU must be revalidated under the new
+// thermal state instead of assuming its previous single-step limit is still
+// valid. The selected reduced power limits stay active for the main benchmark
+// and are restored by the caller afterwards.
 func runBenchmarkPowerCalibration(
 	ctx context.Context,
 	verboseLog, runDir string,
 	gpuIndices []int,
 	infoByIndex map[int]benchmarkGPUInfo,
 	logFunc func(string),
-	fixedLimits map[int]int,
+	seedLimits map[int]int,
 ) (map[int]benchmarkPowerCalibrationResult, []benchmarkRestoreAction) {
 	const calibDurationSec = 120
 	const maxDerateW = 150
@@ -2739,7 +2814,6 @@ func runBenchmarkPowerCalibration(
 		err  error
 	}
 
-
 	// gpuCalibState holds per-GPU binary search state during parallel calibration.
 	type gpuCalibState struct {
 		idx            int
@@ -2796,19 +2870,20 @@ func runBenchmarkPowerCalibration(
 			hi:             appliedLimitW + 1, // not yet tested, not yet confirmed unstable
 			calib:          benchmarkPowerCalibrationResult{AppliedPowerLimitW: float64(appliedLimitW)},
 		}
-		if fixedLimits != nil {
-			if fixedW, ok := fixedLimits[idx]; ok {
-				// This GPU's limit was established in a prior ramp step and must
-				// remain unchanged. Apply it immediately and skip the binary search.
-				if canDerate && fixedW > 0 {
-					_ = setBenchmarkPowerLimit(ctx, verboseLog, idx, fixedW)
+		if seedLimits != nil {
+			if seedW, ok := seedLimits[idx]; ok && seedW > 0 {
+				// A previously validated limit is only a starting point. Re-run
+				// targeted_power under the current multi-GPU thermal load and derate
+				// again if this step shows new throttling.
+				if canDerate {
+					_ = setBenchmarkPowerLimit(ctx, verboseLog, idx, seedW)
 				}
-				s.appliedLimitW = fixedW
-				s.calib.AppliedPowerLimitW = float64(fixedW)
-				s.calib.Completed = true
-				s.converged = true
+				s.appliedLimitW = seedW
+				s.hi = seedW + 1
+				s.calib.AppliedPowerLimitW = float64(seedW)
+				s.calib.Derated = seedW < s.originalLimitW
 				s.calib.Notes = append(s.calib.Notes,
-					fmt.Sprintf("fixed limit: %d W (held from prior ramp step)", fixedW))
+					fmt.Sprintf("seed limit: %d W (revalidating under current thermal load)", seedW))
 			}
 		}
 		states = append(states, s)
@@ -3091,7 +3166,6 @@ func powerBenchDurationSec(profile string) int {
 	}
 }
 
-
 func cloneBenchmarkGPUInfoMap(src map[int]benchmarkGPUInfo) map[int]benchmarkGPUInfo {
 	out := make(map[int]benchmarkGPUInfo, len(src))
 	for k, v := range src {
@@ -3107,7 +3181,42 @@ func renderPowerBenchReport(result NvidiaPowerBenchResult) string {
 	fmt.Fprintf(&b, "**Profile:** %s  \n", result.BenchmarkProfile)
 	fmt.Fprintf(&b, "**Generated:** %s  \n", result.GeneratedAt.Format("2006-01-02 15:04:05 UTC"))
 	fmt.Fprintf(&b, "**Overall status:** %s  \n", result.OverallStatus)
-	fmt.Fprintf(&b, "**Platform max TDP:** %.0f W  \n\n", result.PlatformMaxTDPW)
+	fmt.Fprintf(&b, "**Platform max TDP (GPU-reported):** %.0f W  \n", result.PlatformMaxTDPW)
+	if sp := result.ServerPower; sp != nil && sp.Available {
+		fmt.Fprintf(&b, "**Server power delta (IPMI):** %.0f W  \n", sp.DeltaW)
+		fmt.Fprintf(&b, "**Reporting ratio (IPMI Δ / GPU sum):** %.2f  \n", sp.ReportingRatio)
+	}
+	b.WriteString("\n")
+	// Server power comparison table.
+	if sp := result.ServerPower; sp != nil {
+		b.WriteString("## Server vs GPU Power Comparison\n\n")
+		b.WriteString("| Metric | Value |\n")
+		b.WriteString("|--------|-------|\n")
+		fmt.Fprintf(&b, "| GPU stable limits sum (nvidia-smi) | %.0f W |\n", result.PlatformMaxTDPW)
+		if sp.Available {
+			fmt.Fprintf(&b, "| Server idle power (IPMI) | %.0f W |\n", sp.IdleW)
+			fmt.Fprintf(&b, "| Server loaded power (IPMI) | %.0f W |\n", sp.LoadedW)
+			fmt.Fprintf(&b, "| Server Δ power (loaded − idle) | %.0f W |\n", sp.DeltaW)
+			ratio := sp.ReportingRatio
+			ratioNote := ""
+			switch {
+			case ratio >= 0.9:
+				ratioNote = "✓ GPU telemetry matches server power"
+			case ratio >= 0.75:
+				ratioNote = "⚠ minor discrepancy — GPU may slightly over-report TDP"
+			default:
+				ratioNote = "✗ significant discrepancy — GPU over-reports TDP vs wall power"
+			}
+			fmt.Fprintf(&b, "| Reporting ratio (IPMI Δ / GPU sum) | %.2f — %s |\n", ratio, ratioNote)
+		} else {
+			b.WriteString("| IPMI availability | not available — IPMI not supported or ipmitool not found |\n")
+		}
+		for _, note := range sp.Notes {
+			fmt.Fprintf(&b, "\n> %s\n", note)
+		}
+		b.WriteString("\n")
+	}
+
 	if len(result.Findings) > 0 {
 		b.WriteString("## Summary\n\n")
 		for _, finding := range result.Findings {
@@ -3181,6 +3290,12 @@ func renderPowerBenchSummary(result NvidiaPowerBenchResult) string {
 			fmt.Fprintf(&b, "gpu_%d_stable_limit_w=%.0f\n", gpu.Index, gpu.StablePowerLimitW)
 		}
 	}
+	if sp := result.ServerPower; sp != nil && sp.Available {
+		fmt.Fprintf(&b, "server_idle_w=%.0f\n", sp.IdleW)
+		fmt.Fprintf(&b, "server_loaded_w=%.0f\n", sp.LoadedW)
+		fmt.Fprintf(&b, "server_delta_w=%.0f\n", sp.DeltaW)
+		fmt.Fprintf(&b, "server_reporting_ratio=%.2f\n", sp.ReportingRatio)
+	}
 	return b.String()
 }
 
@@ -3224,6 +3339,16 @@ func (s *System) RunNvidiaPowerBench(ctx context.Context, baseDir string, opts N
 	}
 	durationSec := powerBenchDurationSec(opts.Profile)
 	_ = durationSec
+
+	// Sample IPMI idle power before any GPU load.
+	var serverIdleW float64
+	var serverIdleOK bool
+	if w, ok := sampleIPMIPowerSeries(ctx, 10); ok {
+		serverIdleW = w
+		serverIdleOK = true
+		logFunc(fmt.Sprintf("server idle power (IPMI): %.0f W", w))
+	}
+
 	// Phase 1: calibrate each GPU individually (sequentially, one at a time) to
 	// establish a true single-card power baseline unaffected by neighbour heat.
 	calibByIndex := make(map[int]benchmarkPowerCalibrationResult, len(selected))
@@ -3320,20 +3445,35 @@ func (s *System) RunNvidiaPowerBench(ctx context.Context, baseDir string, opts N
 	// stableLimits accumulates GPU index → fixed stable limit (W) across steps.
 	stableLimits := make(map[int]int, len(result.RecommendedSlotOrder))
 
+	// Start an IPMI sampling goroutine that runs throughout Phase 2 to capture
+	// server-side loaded power while GPUs are under stress. The goroutine is
+	// cancelled as soon as Phase 2 finishes, and the average is used to compare
+	// against PlatformMaxTDPW (GPU-reported stable limits sum).
+	var serverLoadedW float64
+	var serverLoadedOK bool
+	ipmiPhase2Ctx, ipmiPhase2Cancel := context.WithCancel(ctx)
+	ipmiPhase2Done := make(chan float64, 1)
+	go func() {
+		defer close(ipmiPhase2Done)
+		if w, ok := sampleIPMIPowerSeries(ipmiPhase2Ctx, 3600); ok {
+			ipmiPhase2Done <- w
+		}
+	}()
+
 	// Step 1: reuse single-card calibration result directly.
 	if len(result.RecommendedSlotOrder) > 0 {
 		firstIdx := result.RecommendedSlotOrder[0]
 		firstCalib := calibByIndex[firstIdx]
 		stableLimits[firstIdx] = int(math.Round(firstCalib.AppliedPowerLimitW))
 		ramp := NvidiaPowerBenchStep{
-			StepIndex:         1,
-			GPUIndices:        []int{firstIdx},
-			NewGPUIndex:       firstIdx,
-			NewGPUStableLimitW: firstCalib.AppliedPowerLimitW,
+			StepIndex:           1,
+			GPUIndices:          []int{firstIdx},
+			NewGPUIndex:         firstIdx,
+			NewGPUStableLimitW:  firstCalib.AppliedPowerLimitW,
 			TotalObservedPowerW: firstCalib.Summary.P95PowerW,
 			AvgObservedPowerW:   firstCalib.Summary.P95PowerW,
-			Derated:           firstCalib.Derated,
-			Status:            "OK",
+			Derated:             firstCalib.Derated,
+			Status:              "OK",
 		}
 		if !firstCalib.Completed {
 			ramp.Status = "FAILED"
@@ -3351,8 +3491,9 @@ func (s *System) RunNvidiaPowerBench(ctx context.Context, baseDir string, opts N
 			len(result.RecommendedSlotOrder), firstIdx, firstCalib.AppliedPowerLimitW))
 	}
 
-	// Steps 2..N: each step fixes previously calibrated GPUs and searches only
-	// the new GPU's stable limit in the combined thermal environment.
+	// Steps 2..N: each step revalidates every already-active GPU under the new
+	// cumulative thermal environment and also calibrates the newly introduced
+	// GPU. Previously found limits are used only as seeds for the search.
 	for stepNum := 1; stepNum < len(result.RecommendedSlotOrder); stepNum++ {
 		step := stepNum + 1
 		subset := append([]int(nil), result.RecommendedSlotOrder[:step]...)
@@ -3360,17 +3501,18 @@ func (s *System) RunNvidiaPowerBench(ctx context.Context, baseDir string, opts N
 		stepDir := filepath.Join(runDir, fmt.Sprintf("step-%02d", step))
 		_ = os.MkdirAll(stepDir, 0755)
 
-		// All previously calibrated GPUs are fixed at their stable limits.
-		fixedForStep := make(map[int]int, len(stableLimits))
+		// Reuse the latest stable limits as starting points, but re-check every
+		// active GPU in this hotter configuration.
+		seedForStep := make(map[int]int, len(stableLimits))
 		for k, v := range stableLimits {
-			fixedForStep[k] = v
+			seedForStep[k] = v
 		}
 
-		logFunc(fmt.Sprintf("power ramp: step %d/%d — calibrating GPU %d with %d fixed GPU(s)",
-			step, len(result.RecommendedSlotOrder), newGPUIdx, len(fixedForStep)))
+		logFunc(fmt.Sprintf("power ramp: step %d/%d — revalidating %d active GPU(s) including new GPU %d",
+			step, len(result.RecommendedSlotOrder), len(subset), newGPUIdx))
 
 		stepInfo := cloneBenchmarkGPUInfoMap(infoByIndex)
-		stepCalib, stepRestore := runBenchmarkPowerCalibration(ctx, verboseLog, stepDir, subset, stepInfo, logFunc, fixedForStep)
+		stepCalib, stepRestore := runBenchmarkPowerCalibration(ctx, verboseLog, stepDir, subset, stepInfo, logFunc, seedForStep)
 		// Accumulate restore actions; they all run in the outer defer.
 		allRestoreActions = append(allRestoreActions, stepRestore...)
 
@@ -3391,36 +3533,72 @@ func (s *System) RunNvidiaPowerBench(ctx context.Context, baseDir string, opts N
 			ramp.AvgObservedPowerW = ramp.TotalObservedPowerW / float64(len(subset))
 		}
 
-		// Determine stable limit for the new GPU.
-		if c, ok := stepCalib[newGPUIdx]; ok && c.Completed {
-			stableLimits[newGPUIdx] = int(math.Round(c.AppliedPowerLimitW))
-			ramp.NewGPUStableLimitW = c.AppliedPowerLimitW
-			ramp.Derated = c.Derated
+		for _, idx := range subset {
+			c, ok := stepCalib[idx]
+			if !ok || !c.Completed {
+				fallback := 0
+				if lim, ok := stableLimits[idx]; ok && lim > 0 {
+					fallback = lim
+				} else if fb, ok := calibByIndex[idx]; ok {
+					fallback = int(math.Round(fb.AppliedPowerLimitW))
+				}
+				if fallback > 0 {
+					stableLimits[idx] = fallback
+				}
+				ramp.Status = "FAILED"
+				ramp.Notes = append(ramp.Notes,
+					fmt.Sprintf("GPU %d did not complete targeted_power in ramp step %d; keeping previous stable limit %d W", idx, step, fallback))
+				result.OverallStatus = "PARTIAL"
+				continue
+			}
+
+			prevLimit, hadPrev := stableLimits[idx]
+			newLimit := int(math.Round(c.AppliedPowerLimitW))
+			stableLimits[idx] = newLimit
+			if idx == newGPUIdx {
+				ramp.NewGPUStableLimitW = c.AppliedPowerLimitW
+				ramp.Derated = c.Derated
+			}
 			if c.Derated {
 				ramp.Status = "PARTIAL"
 				if result.OverallStatus == "OK" {
 					result.OverallStatus = "PARTIAL"
 				}
-				result.Findings = append(result.Findings, fmt.Sprintf("Ramp step %d (GPU %d) required derating to %.0f W under combined thermal load.", step, newGPUIdx, c.AppliedPowerLimitW))
 			}
-		} else {
-			// Calibration failed — fall back to single-card limit.
-			fb := calibByIndex[newGPUIdx]
-			stableLimits[newGPUIdx] = int(math.Round(fb.AppliedPowerLimitW))
-			ramp.NewGPUStableLimitW = fb.AppliedPowerLimitW
-			ramp.Status = "FAILED"
-			ramp.Notes = append(ramp.Notes, fmt.Sprintf("GPU %d did not complete targeted_power in ramp step %d; using single-card limit %.0f W", newGPUIdx, step, fb.AppliedPowerLimitW))
-			result.OverallStatus = "PARTIAL"
+			if hadPrev && newLimit < prevLimit {
+				ramp.Notes = append(ramp.Notes,
+					fmt.Sprintf("GPU %d was re-derated from %d W to %d W under combined thermal load.", idx, prevLimit, newLimit))
+			}
+		}
+
+		if c, ok := stepCalib[newGPUIdx]; ok && c.Completed && c.Derated {
+			result.Findings = append(result.Findings, fmt.Sprintf("Ramp step %d (GPU %d) required derating to %.0f W under combined thermal load.", step, newGPUIdx, c.AppliedPowerLimitW))
 		}
 
 		result.RampSteps = append(result.RampSteps, ramp)
 	}
 
+	// Stop IPMI Phase 2 sampling and collect result.
+	ipmiPhase2Cancel()
+	if w, ok := <-ipmiPhase2Done; ok {
+		serverLoadedW = w
+		serverLoadedOK = true
+		logFunc(fmt.Sprintf("server loaded power (IPMI, Phase 2 avg): %.0f W", w))
+	}
+
 	// Populate StablePowerLimitW on each GPU entry from the accumulated stable limits.
 	for i := range result.GPUs {
 		if lim, ok := stableLimits[result.GPUs[i].Index]; ok {
 			result.GPUs[i].StablePowerLimitW = float64(lim)
 		}
+		if result.GPUs[i].StablePowerLimitW > 0 && result.GPUs[i].AppliedPowerLimitW > 0 &&
+			result.GPUs[i].StablePowerLimitW < result.GPUs[i].AppliedPowerLimitW {
+			result.GPUs[i].Derated = true
+			result.Findings = append(result.Findings, fmt.Sprintf(
+				"GPU %d required additional derating from %.0f W (single-card) to %.0f W under full-system thermal load.",
+				result.GPUs[i].Index, result.GPUs[i].AppliedPowerLimitW, result.GPUs[i].StablePowerLimitW,
+			))
+		}
 	}
 
 	// PlatformMaxTDPW = sum of all stable limits — the actual sustained power
@@ -3428,6 +3606,13 @@ func (s *System) RunNvidiaPowerBench(ctx context.Context, baseDir string, opts N
 	for _, lim := range stableLimits {
 		result.PlatformMaxTDPW += float64(lim)
 	}
+
+	// Characterize server power from IPMI idle/loaded samples.
+	// GPUReportedSumW = PlatformMaxTDPW (sum of stable GPU limits, nvidia-smi).
+	// ReportingRatio = IPMI_delta / GPU_reported_sum:
+	//   ~1.0 → GPU telemetry matches wall power; <0.75 → GPU over-reports its TDP.
+	_ = serverIdleOK // used implicitly via characterizeServerPower
+	result.ServerPower = characterizeServerPower(serverIdleW, serverLoadedW, result.PlatformMaxTDPW, serverIdleOK && serverLoadedOK)
 	resultJSON, err := json.MarshalIndent(result, "", "  ")
 	if err != nil {
 		return "", fmt.Errorf("marshal power result: %w", err)

audit/internal/platform/benchmark_report.go

@@ -261,14 +261,18 @@ func renderBenchmarkReportWithCharts(result NvidiaBenchmarkResult) string {
 		b.WriteString("\n")
 
 		// Steady-state telemetry
-		fmt.Fprintf(&b, "**Steady-state telemetry** (%ds):\n\n", int(gpu.Steady.DurationSec))
-		b.WriteString("| | Avg | P95 |\n|---|---|---|\n")
-		fmt.Fprintf(&b, "| Power | %.1f W | %.1f W |\n", gpu.Steady.AvgPowerW, gpu.Steady.P95PowerW)
-		fmt.Fprintf(&b, "| Temperature | %.1f °C | %.1f °C |\n", gpu.Steady.AvgTempC, gpu.Steady.P95TempC)
-		fmt.Fprintf(&b, "| GPU clock | %.0f MHz | %.0f MHz |\n", gpu.Steady.AvgGraphicsClockMHz, gpu.Steady.P95GraphicsClockMHz)
-		fmt.Fprintf(&b, "| Memory clock | %.0f MHz | %.0f MHz |\n", gpu.Steady.AvgMemoryClockMHz, gpu.Steady.P95MemoryClockMHz)
-		fmt.Fprintf(&b, "| GPU utilisation | %.1f %% | — |\n", gpu.Steady.AvgUsagePct)
-		b.WriteString("\n")
+		if benchmarkTelemetryAvailable(gpu.Steady) {
+			fmt.Fprintf(&b, "**Steady-state telemetry** (%ds):\n\n", int(gpu.Steady.DurationSec))
+			b.WriteString("| | Avg | P95 |\n|---|---|---|\n")
+			fmt.Fprintf(&b, "| Power | %.1f W | %.1f W |\n", gpu.Steady.AvgPowerW, gpu.Steady.P95PowerW)
+			fmt.Fprintf(&b, "| Temperature | %.1f °C | %.1f °C |\n", gpu.Steady.AvgTempC, gpu.Steady.P95TempC)
+			fmt.Fprintf(&b, "| GPU clock | %.0f MHz | %.0f MHz |\n", gpu.Steady.AvgGraphicsClockMHz, gpu.Steady.P95GraphicsClockMHz)
+			fmt.Fprintf(&b, "| Memory clock | %.0f MHz | %.0f MHz |\n", gpu.Steady.AvgMemoryClockMHz, gpu.Steady.P95MemoryClockMHz)
+			fmt.Fprintf(&b, "| GPU utilisation | %.1f %% | — |\n", gpu.Steady.AvgUsagePct)
+			b.WriteString("\n")
+		} else {
+			b.WriteString("**Steady-state telemetry:** unavailable\n\n")
+		}
 
 		// Per-precision stability phases.
 		if len(gpu.PrecisionSteady) > 0 {

audit/internal/platform/benchmark_test.go

@@ -49,8 +49,8 @@ func TestBuildBenchmarkSteadyPlanStandard(t *testing.T) {
 		benchmarkPrecisionPhases,
 		func(label string) string { return label },
 	)
-	if len(labels) != 7 || len(phases) != 7 {
-		t.Fatalf("labels=%d phases=%d want 7", len(labels), len(phases))
+	if len(labels) != 5 || len(phases) != 5 {
+		t.Fatalf("labels=%d phases=%d want 5", len(labels), len(phases))
 	}
 	if basePhaseSec != 60 {
 		t.Fatalf("basePhaseSec=%d want 60", basePhaseSec)
@@ -61,7 +61,7 @@ func TestBuildBenchmarkSteadyPlanStandard(t *testing.T) {
 	if phases[len(phases)-1].PlanLabel != "mixed" || phases[len(phases)-1].DurationSec != 300 {
 		t.Fatalf("mixed phase=%+v want duration 300", phases[len(phases)-1])
 	}
-	if benchmarkPlanDurationsCSV(phases) != "60,60,60,60,60,60,300" {
+	if benchmarkPlanDurationsCSV(phases) != "60,60,60,60,300" {
 		t.Fatalf("durations=%q", benchmarkPlanDurationsCSV(phases))
 	}
 }
@@ -80,7 +80,7 @@ func TestBuildBenchmarkSteadyPlanStability(t *testing.T) {
 	if mixedPhaseSec != 3600 {
 		t.Fatalf("mixedPhaseSec=%d want 3600", mixedPhaseSec)
 	}
-	if benchmarkPlanDurationsCSV(phases) != "300,300,300,300,300,300,3600" {
+	if benchmarkPlanDurationsCSV(phases) != "300,300,300,300,3600" {
 		t.Fatalf("durations=%q", benchmarkPlanDurationsCSV(phases))
 	}
 }
@@ -99,7 +99,7 @@ func TestBuildBenchmarkSteadyPlanOvernight(t *testing.T) {
 	if mixedPhaseSec != 14400 {
 		t.Fatalf("mixedPhaseSec=%d want 14400", mixedPhaseSec)
 	}
-	if benchmarkPlanDurationsCSV(phases) != "3600,3600,3600,3600,3600,3600,14400" {
+	if benchmarkPlanDurationsCSV(phases) != "3600,3600,3600,3600,14400" {
 		t.Fatalf("durations=%q", benchmarkPlanDurationsCSV(phases))
 	}
 }
@@ -133,10 +133,10 @@ func TestSplitBenchmarkRowsByPlannedPhaseUsesPhaseDurations(t *testing.T) {
 func TestBenchmarkSupportedPrecisionsSkipsFP4BeforeBlackwell(t *testing.T) {
 	t.Parallel()
 
-	if got := benchmarkSupportedPrecisions("9.0"); strings.Join(got, ",") != "int8,fp8,fp16,fp32,fp64" {
+	if got := benchmarkSupportedPrecisions("9.0"); strings.Join(got, ",") != "int8,fp8,fp16,fp32" {
 		t.Fatalf("supported=%v", got)
 	}
-	if got := benchmarkSupportedPrecisions("10.0"); strings.Join(got, ",") != "int8,fp8,fp16,fp32,fp64,fp4" {
+	if got := benchmarkSupportedPrecisions("10.0"); strings.Join(got, ",") != "int8,fp8,fp16,fp32" {
 		t.Fatalf("supported=%v", got)
 	}
 }
@@ -314,6 +314,30 @@ func TestRenderBenchmarkReportListsUnifiedArtifacts(t *testing.T) {
 	}
 }
 
+func TestScoreBenchmarkGPUIgnoresDisabledPrecisions(t *testing.T) {
+	t.Parallel()
+
+	score := scoreBenchmarkGPUResult(BenchmarkGPUResult{
+		PrecisionSteady: []BenchmarkPrecisionSteadyPhase{
+			{Precision: "fp16", WeightedTeraOpsPerSec: 100},
+			{Precision: "fp64", WeightedTeraOpsPerSec: 999},
+			{Precision: "fp4", WeightedTeraOpsPerSec: 999},
+		},
+		PrecisionResults: []BenchmarkPrecisionResult{
+			{Category: "fp32_tf32", Supported: true, WeightedTeraOpsPerSec: 50},
+			{Category: "fp64", Supported: true, WeightedTeraOpsPerSec: 999},
+			{Category: "fp4", Supported: true, WeightedTeraOpsPerSec: 999},
+		},
+	})
+
+	if score.SyntheticScore != 100 {
+		t.Fatalf("SyntheticScore=%f want 100", score.SyntheticScore)
+	}
+	if score.MixedScore != 50 {
+		t.Fatalf("MixedScore=%f want 50", score.MixedScore)
+	}
+}
+
 func TestEnrichGPUInfoWithMaxClocks(t *testing.T) {
 	t.Parallel()
 

audit/internal/platform/benchmark_types.go

@@ -31,6 +31,7 @@ type BenchmarkCoolingSummary struct {
 	Available             bool     `json:"available"`
 	AvgFanRPM             float64  `json:"avg_fan_rpm,omitempty"`
 	FanDutyCycleAvailable bool     `json:"fan_duty_cycle_available,omitempty"`
+	FanDutyCycleEstimated bool     `json:"fan_duty_cycle_estimated,omitempty"`
 	AvgFanDutyCyclePct    float64  `json:"avg_fan_duty_cycle_pct,omitempty"`
 	P95FanDutyCyclePct    float64  `json:"p95_fan_duty_cycle_pct,omitempty"`
 	Notes                 []string `json:"notes,omitempty"`
@@ -55,32 +56,32 @@ type NvidiaBenchmarkOptions struct {
 }
 
 type NvidiaBenchmarkResult struct {
-	BenchmarkVersion   string                       `json:"benchmark_version"`
-	GeneratedAt        time.Time                    `json:"generated_at"`
-	Hostname           string                       `json:"hostname,omitempty"`
-	ServerModel        string                       `json:"server_model,omitempty"`
-	BenchmarkProfile   string                       `json:"benchmark_profile"`
-	ParallelGPUs       bool                         `json:"parallel_gpus,omitempty"`
-	RampStep           int                          `json:"ramp_step,omitempty"`
-	RampTotal          int                          `json:"ramp_total,omitempty"`
-	RampRunID          string                       `json:"ramp_run_id,omitempty"`
-	ScalabilityScore   float64                      `json:"scalability_score,omitempty"`
+	BenchmarkVersion string    `json:"benchmark_version"`
+	GeneratedAt      time.Time `json:"generated_at"`
+	Hostname         string    `json:"hostname,omitempty"`
+	ServerModel      string    `json:"server_model,omitempty"`
+	BenchmarkProfile string    `json:"benchmark_profile"`
+	ParallelGPUs     bool      `json:"parallel_gpus,omitempty"`
+	RampStep         int       `json:"ramp_step,omitempty"`
+	RampTotal        int       `json:"ramp_total,omitempty"`
+	RampRunID        string    `json:"ramp_run_id,omitempty"`
+	ScalabilityScore float64   `json:"scalability_score,omitempty"`
 	// PlatformPowerScore is the mean compute scalability across ramp steps 2..N.
 	// 100% = each added GPU contributes exactly its single-card throughput.
 	// < 100% = throughput loss due to thermal throttle, power limits, or contention.
-	PlatformPowerScore   float64                    `json:"platform_power_score,omitempty"`
-	PerformanceRampSteps []NvidiaPerformanceRampStep `json:"performance_ramp_steps,omitempty"`
-	OverallStatus      string                       `json:"overall_status"`
-	SelectedGPUIndices []int                        `json:"selected_gpu_indices"`
-	Findings           []string                     `json:"findings,omitempty"`
-	Warnings           []string                     `json:"warnings,omitempty"`
-	Normalization      BenchmarkNormalization       `json:"normalization"`
-	HostConfig         *BenchmarkHostConfig         `json:"host_config,omitempty"`
-	CPULoad            *BenchmarkCPULoad            `json:"cpu_load,omitempty"`
-	Cooling            *BenchmarkCoolingSummary     `json:"cooling,omitempty"`
-	GPUs               []BenchmarkGPUResult         `json:"gpus"`
-	Interconnect       *BenchmarkInterconnectResult `json:"interconnect,omitempty"`
-	ServerPower        *BenchmarkServerPower        `json:"server_power,omitempty"`
+	PlatformPowerScore   float64                      `json:"platform_power_score,omitempty"`
+	PerformanceRampSteps []NvidiaPerformanceRampStep  `json:"performance_ramp_steps,omitempty"`
+	OverallStatus        string                       `json:"overall_status"`
+	SelectedGPUIndices   []int                        `json:"selected_gpu_indices"`
+	Findings             []string                     `json:"findings,omitempty"`
+	Warnings             []string                     `json:"warnings,omitempty"`
+	Normalization        BenchmarkNormalization       `json:"normalization"`
+	HostConfig           *BenchmarkHostConfig         `json:"host_config,omitempty"`
+	CPULoad              *BenchmarkCPULoad            `json:"cpu_load,omitempty"`
+	Cooling              *BenchmarkCoolingSummary     `json:"cooling,omitempty"`
+	GPUs                 []BenchmarkGPUResult         `json:"gpus"`
+	Interconnect         *BenchmarkInterconnectResult `json:"interconnect,omitempty"`
+	ServerPower          *BenchmarkServerPower        `json:"server_power,omitempty"`
 }
 
 type BenchmarkNormalization struct {
@@ -223,8 +224,8 @@ type BenchmarkScorecard struct {
 
 	// Throttle breakdown — percentage of steady-state time in each throttle type.
 	// Used for diagnosis: tells WHY the GPU throttled, not just whether it did.
-	ThermalThrottlePct  float64 `json:"thermal_throttle_pct"`  // HW+SW thermal slowdown
-	PowerCapThrottlePct float64 `json:"power_cap_throttle_pct"` // SW power cap
+	ThermalThrottlePct   float64 `json:"thermal_throttle_pct"`   // HW+SW thermal slowdown
+	PowerCapThrottlePct  float64 `json:"power_cap_throttle_pct"` // SW power cap
 	SyncBoostThrottlePct float64 `json:"sync_boost_throttle_pct,omitempty"`
 
 	// Temperature headroom: distance to the 100°C destruction threshold.
@@ -300,18 +301,22 @@ type NvidiaPowerBenchResult struct {
 	// PlatformMaxTDPW is the sum of per-GPU stable power limits found during the
 	// cumulative thermal ramp. Represents the actual sustained power budget of
 	// this server under full GPU load. Use for rack power planning.
-	PlatformMaxTDPW float64  `json:"platform_max_tdp_w"`
-	Findings        []string `json:"findings,omitempty"`
-	GPUs            []NvidiaPowerBenchGPU `json:"gpus"`
+	PlatformMaxTDPW float64 `json:"platform_max_tdp_w"`
+	// ServerPower captures IPMI server power delta (idle→loaded) measured in
+	// parallel with the thermal ramp. Use to compare GPU-reported TDP against
+	// actual wall-power draw as seen by the server's power supply.
+	ServerPower *BenchmarkServerPower `json:"server_power,omitempty"`
+	Findings    []string              `json:"findings,omitempty"`
+	GPUs        []NvidiaPowerBenchGPU `json:"gpus"`
 }
 
 type NvidiaPowerBenchGPU struct {
-	Index               int      `json:"index"`
-	Name                string   `json:"name,omitempty"`
-	BusID               string   `json:"bus_id,omitempty"`
-	DefaultPowerLimitW  float64  `json:"default_power_limit_w,omitempty"`
+	Index              int     `json:"index"`
+	Name               string  `json:"name,omitempty"`
+	BusID              string  `json:"bus_id,omitempty"`
+	DefaultPowerLimitW float64 `json:"default_power_limit_w,omitempty"`
 	// AppliedPowerLimitW is the stable limit found during single-card calibration.
-	AppliedPowerLimitW  float64  `json:"applied_power_limit_w,omitempty"`
+	AppliedPowerLimitW float64 `json:"applied_power_limit_w,omitempty"`
 	// StablePowerLimitW is the final fixed limit for this GPU after the
 	// cumulative thermal ramp. This is the limit at which the GPU operated
 	// stably with all other GPUs running simultaneously at their own limits.
@@ -329,10 +334,10 @@ type NvidiaPowerBenchGPU struct {
 }
 
 type NvidiaPowerBenchStep struct {
-	StepIndex           int      `json:"step_index"`
-	GPUIndices          []int    `json:"gpu_indices"`
+	StepIndex  int   `json:"step_index"`
+	GPUIndices []int `json:"gpu_indices"`
 	// NewGPUIndex is the GPU whose stable limit was searched in this step.
-	NewGPUIndex         int      `json:"new_gpu_index"`
+	NewGPUIndex int `json:"new_gpu_index"`
 	// NewGPUStableLimitW is the stable power limit found for the new GPU.
 	NewGPUStableLimitW  float64  `json:"new_gpu_stable_limit_w,omitempty"`
 	TotalObservedPowerW float64  `json:"total_observed_power_w,omitempty"`
@@ -345,15 +350,15 @@ type NvidiaPowerBenchStep struct {
 // NvidiaPerformanceRampStep holds per-step performance data for the
 // scalability ramp-up phase of the performance benchmark.
 type NvidiaPerformanceRampStep struct {
-	StepIndex          int      `json:"step_index"`
-	GPUIndices         []int    `json:"gpu_indices"`
+	StepIndex  int   `json:"step_index"`
+	GPUIndices []int `json:"gpu_indices"`
 	// TotalSyntheticTOPS is the sum of per-GPU SyntheticScore (fp32-equivalent
 	// TOPS from dedicated single-precision phases) across all GPUs in this step.
-	TotalSyntheticTOPS float64  `json:"total_synthetic_tops"`
-	TotalMixedTOPS     float64  `json:"total_mixed_tops,omitempty"`
+	TotalSyntheticTOPS float64 `json:"total_synthetic_tops"`
+	TotalMixedTOPS     float64 `json:"total_mixed_tops,omitempty"`
 	// ScalabilityPct = TotalSyntheticTOPS / (k × best_single_gpu_tops) × 100.
 	// 100% = perfect linear scaling. < 100% = thermal/power/interconnect loss.
-	ScalabilityPct     float64  `json:"scalability_pct"`
-	Status             string   `json:"status"`
-	Notes              []string `json:"notes,omitempty"`
+	ScalabilityPct float64  `json:"scalability_pct"`
+	Status         string   `json:"status"`
+	Notes          []string `json:"notes,omitempty"`
 }

audit/internal/platform/gpu_metrics.go

@@ -27,6 +27,7 @@ type GPUMetricRow struct {
 	FanAvgRPM             float64 `json:"fan_avg_rpm,omitempty"`
 	FanDutyCyclePct       float64 `json:"fan_duty_cycle_pct,omitempty"`
 	FanDutyCycleAvailable bool    `json:"fan_duty_cycle_available,omitempty"`
+	FanDutyCycleEstimated bool    `json:"fan_duty_cycle_estimated,omitempty"`
 }
 
 // sampleGPUMetrics runs nvidia-smi once and returns current metrics for each GPU.
@@ -147,14 +148,18 @@ func sampleAMDGPUMetrics() ([]GPUMetricRow, error) {
 // WriteGPUMetricsCSV writes collected rows as a CSV file.
 func WriteGPUMetricsCSV(path string, rows []GPUMetricRow) error {
 	var b bytes.Buffer
-	b.WriteString("stage,elapsed_sec,gpu_index,temperature_c,usage_pct,mem_usage_pct,power_w,clock_mhz,mem_clock_mhz,fan_avg_rpm,fan_duty_cycle_pct,fan_duty_cycle_available\n")
+	b.WriteString("stage,elapsed_sec,gpu_index,temperature_c,usage_pct,mem_usage_pct,power_w,clock_mhz,mem_clock_mhz,fan_avg_rpm,fan_duty_cycle_pct,fan_duty_cycle_available,fan_duty_cycle_estimated\n")
 	for _, r := range rows {
 		dutyAvail := 0
 		if r.FanDutyCycleAvailable {
 			dutyAvail = 1
 		}
-		fmt.Fprintf(&b, "%s,%.1f,%d,%.1f,%.1f,%.1f,%.1f,%.0f,%.0f,%.0f,%.1f,%d\n",
-			strconv.Quote(strings.TrimSpace(r.Stage)), r.ElapsedSec, r.GPUIndex, r.TempC, r.UsagePct, r.MemUsagePct, r.PowerW, r.ClockMHz, r.MemClockMHz, r.FanAvgRPM, r.FanDutyCyclePct, dutyAvail)
+		dutyEstimated := 0
+		if r.FanDutyCycleEstimated {
+			dutyEstimated = 1
+		}
+		fmt.Fprintf(&b, "%s,%.1f,%d,%.1f,%.1f,%.1f,%.1f,%.0f,%.0f,%.0f,%.1f,%d,%d\n",
+			strconv.Quote(strings.TrimSpace(r.Stage)), r.ElapsedSec, r.GPUIndex, r.TempC, r.UsagePct, r.MemUsagePct, r.PowerW, r.ClockMHz, r.MemClockMHz, r.FanAvgRPM, r.FanDutyCyclePct, dutyAvail, dutyEstimated)
 	}
 	return os.WriteFile(path, b.Bytes(), 0644)
 }

audit/internal/platform/sat_fan_stress.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"encoding/json"
 	"fmt"
+	"math"
 	"os"
 	"os/exec"
 	"path/filepath"
@@ -56,13 +57,37 @@ type cachedPowerReading struct {
 	UpdatedAt time.Time
 }
 
+type fanObservationState struct {
+	MaxRPM map[string]float64 `json:"max_rpm"`
+}
+
+type fanPeakCandidate struct {
+	FirstSeen time.Time
+	RPM       float64
+}
+
 var (
 	systemPowerCacheMu sync.Mutex
 	systemPowerCache   cachedPowerReading
+	fanObservationMu   sync.Mutex
+	fanObservation     fanObservationState
+	fanObservationInit bool
+	fanPeakCandidates  = make(map[string]fanPeakCandidate)
 )
 
 const systemPowerHoldTTL = 15 * time.Second
 
+var fanObservationStatePath = "/var/log/bee-sat/fan-observation.json"
+
+const fanObservationMinPeakHold = time.Second
+
+func normalizeObservedFanMaxRPM(rpm float64) float64 {
+	if rpm <= 0 {
+		return 0
+	}
+	return math.Ceil(rpm/1000.0) * 1000.0
+}
+
 // RunFanStressTest runs a two-phase GPU stress test while monitoring fan speeds,
 // temperatures, and power draw every second. Exports metrics.csv and fan-sensors.csv.
 // Designed to reproduce case-04 fan-speed lag and detect GPU thermal throttling.
@@ -310,11 +335,13 @@ func sampleFanSpeeds() ([]FanReading, error) {
 	out, err := exec.Command("ipmitool", "sdr", "type", "Fan").Output()
 	if err == nil {
 		if fans := parseFanSpeeds(string(out)); len(fans) > 0 {
+			updateFanObservation(fans, time.Now())
 			return fans, nil
 		}
 	}
 	fans, sensorsErr := sampleFanSpeedsViaSensorsJSON()
 	if len(fans) > 0 {
+		updateFanObservation(fans, time.Now())
 		return fans, nil
 	}
 	if err != nil {
@@ -323,6 +350,119 @@ func sampleFanSpeeds() ([]FanReading, error) {
 	return nil, sensorsErr
 }
 
+func loadFanObservationLocked() {
+	if fanObservationInit {
+		return
+	}
+	fanObservationInit = true
+	fanObservation.MaxRPM = make(map[string]float64)
+	raw, err := os.ReadFile(fanObservationStatePath)
+	if err != nil || len(raw) == 0 {
+		return
+	}
+	var persisted fanObservationState
+	if json.Unmarshal(raw, &persisted) != nil {
+		return
+	}
+	for name, rpm := range persisted.MaxRPM {
+		name = strings.TrimSpace(name)
+		if name == "" || rpm <= 0 {
+			continue
+		}
+		fanObservation.MaxRPM[name] = rpm
+	}
+}
+
+func saveFanObservationLocked() {
+	if len(fanObservation.MaxRPM) == 0 {
+		return
+	}
+	dir := filepath.Dir(fanObservationStatePath)
+	if dir == "" || dir == "." {
+		dir = "/var/log/bee-sat"
+	}
+	if err := os.MkdirAll(dir, 0755); err != nil {
+		return
+	}
+	raw, err := json.MarshalIndent(fanObservation, "", "  ")
+	if err != nil {
+		return
+	}
+	_ = os.WriteFile(fanObservationStatePath, raw, 0644)
+}
+
+func updateFanObservation(fans []FanReading, now time.Time) {
+	if len(fans) == 0 {
+		return
+	}
+	fanObservationMu.Lock()
+	defer fanObservationMu.Unlock()
+	loadFanObservationLocked()
+	changed := false
+	for _, fan := range fans {
+		name := strings.TrimSpace(fan.Name)
+		if name == "" || fan.RPM <= 0 {
+			continue
+		}
+		currentMax := fanObservation.MaxRPM[name]
+		if fan.RPM <= currentMax {
+			delete(fanPeakCandidates, name)
+			continue
+		}
+		if cand, ok := fanPeakCandidates[name]; ok {
+			if now.Sub(cand.FirstSeen) >= fanObservationMinPeakHold {
+				newMax := math.Max(cand.RPM, fan.RPM)
+				if newMax > currentMax {
+					fanObservation.MaxRPM[name] = normalizeObservedFanMaxRPM(newMax)
+					changed = true
+				}
+				delete(fanPeakCandidates, name)
+				continue
+			}
+			if fan.RPM > cand.RPM {
+				fanPeakCandidates[name] = fanPeakCandidate{FirstSeen: cand.FirstSeen, RPM: fan.RPM}
+			}
+			continue
+		}
+		fanPeakCandidates[name] = fanPeakCandidate{FirstSeen: now, RPM: fan.RPM}
+	}
+	if changed {
+		saveFanObservationLocked()
+	}
+}
+
+func estimateFanDutyCyclePctFromObservation(fans []FanReading) (float64, bool) {
+	if len(fans) == 0 {
+		return 0, false
+	}
+	fanObservationMu.Lock()
+	defer fanObservationMu.Unlock()
+	loadFanObservationLocked()
+	var samples []float64
+	for _, fan := range fans {
+		name := strings.TrimSpace(fan.Name)
+		if name == "" || fan.RPM <= 0 {
+			continue
+		}
+		maxRPM := fanObservation.MaxRPM[name]
+		if maxRPM <= 0 {
+			continue
+		}
+		pct := fan.RPM / maxRPM * 100.0
+		if pct > 100 {
+			pct = 100
+		}
+		if pct < 0 {
+			pct = 0
+		}
+		samples = append(samples, pct)
+	}
+	if len(samples) == 0 {
+		return 0, false
+	}
+	return benchmarkMean(samples), true
+}
+
 // parseFanSpeeds parses "ipmitool sdr type Fan" output.
 // Handles two formats:
 //
@@ -428,12 +568,27 @@ func sampleFanSpeedsViaSensorsJSON() ([]FanReading, error) {
 
 // sampleFanDutyCyclePct reads fan PWM/duty-cycle controls from lm-sensors.
 // Returns the average duty cycle across all exposed PWM controls.
-func sampleFanDutyCyclePct() (float64, bool) {
+func sampleFanDutyCyclePct() (float64, bool, bool) {
 	out, err := exec.Command("sensors", "-j").Output()
 	if err != nil || len(out) == 0 {
-		return 0, false
+		fans, fanErr := sampleFanSpeeds()
+		if fanErr != nil {
+			return 0, false, false
+		}
+		return sampleFanDutyCyclePctFromFans(fans)
 	}
-	return parseFanDutyCyclePctSensorsJSON(out)
+	pct, ok := parseFanDutyCyclePctSensorsJSON(out)
+	return pct, ok, false
+}
+
+func sampleFanDutyCyclePctFromFans(fans []FanReading) (float64, bool, bool) {
+	if len(fans) == 0 {
+		return 0, false, false
+	}
+	if pct, ok := estimateFanDutyCyclePctFromObservation(fans); ok {
+		return pct, true, true
+	}
+	return 0, false, false
 }
 
 func parseFanDutyCyclePctSensorsJSON(raw []byte) (float64, bool) {

audit/internal/platform/sat_fan_stress_test.go

@@ -1,6 +1,7 @@
 package platform
 
 import (
+	"path/filepath"
 	"testing"
 	"time"
 )
@@ -50,6 +51,53 @@ func TestParseFanDutyCyclePctSensorsJSON(t *testing.T) {
 	}
 }
 
+func TestEstimateFanDutyCyclePctFromObservation(t *testing.T) {
+	t.Parallel()
+
+	oldPath := fanObservationStatePath
+	oldState := fanObservation
+	oldInit := fanObservationInit
+	oldCandidates := fanPeakCandidates
+	fanObservationStatePath = filepath.Join(t.TempDir(), "fan-observation.json")
+	fanObservation = fanObservationState{}
+	fanObservationInit = false
+	fanPeakCandidates = make(map[string]fanPeakCandidate)
+	t.Cleanup(func() {
+		fanObservationStatePath = oldPath
+		fanObservation = oldState
+		fanObservationInit = oldInit
+		fanPeakCandidates = oldCandidates
+	})
+
+	start := time.Unix(100, 0)
+	updateFanObservation([]FanReading{{Name: "FAN1", RPM: 5000}}, start)
+	if _, ok := estimateFanDutyCyclePctFromObservation([]FanReading{{Name: "FAN1", RPM: 2500}}); ok {
+		t.Fatalf("single-sample spike should not establish observed max")
+	}
+
+	updateFanObservation([]FanReading{{Name: "FAN1", RPM: 5200}}, start.Add(500*time.Millisecond))
+	updateFanObservation([]FanReading{{Name: "FAN1", RPM: 5100}}, start.Add(1500*time.Millisecond))
+
+	got, ok := estimateFanDutyCyclePctFromObservation([]FanReading{{Name: "FAN1", RPM: 2600}})
+	if !ok {
+		t.Fatalf("expected estimated duty cycle from persisted observed max")
+	}
+	if got < 43 || got > 44 {
+		t.Fatalf("got=%v want ~43.3", got)
+	}
+
+	fanObservation = fanObservationState{}
+	fanObservationInit = false
+	fanPeakCandidates = make(map[string]fanPeakCandidate)
+	got, ok = estimateFanDutyCyclePctFromObservation([]FanReading{{Name: "FAN1", RPM: 2600}})
+	if !ok {
+		t.Fatalf("expected persisted observed max to be reloaded from disk")
+	}
+	if got < 43 || got > 44 {
+		t.Fatalf("reloaded got=%v want ~43.3", got)
+	}
+}
+
 func TestParseDCMIPowerReading(t *testing.T) {
 	raw := `
 Instantaneous power reading:                   512 Watts

iso/builder/bee-gpu-stress.c

@@ -713,6 +713,19 @@ static const struct profile_desc k_profiles[] = {
 
 #define PROFILE_COUNT ((int)(sizeof(k_profiles) / sizeof(k_profiles[0])))
 
+static int profile_allowed_for_run(const struct profile_desc *desc, int cc, const char *precision_filter) {
+    if (!(desc->enabled && cc >= desc->min_cc)) {
+        return 0;
+    }
+    if (precision_filter != NULL) {
+        return strcmp(desc->block_label, precision_filter) == 0;
+    }
+    /* Mixed/all phases intentionally exclude fp64/fp4 for now: both paths are
+     * unstable on the current benchmark fleet and can abort the whole mixed
+     * pass after earlier phases already collected useful telemetry. */
+    return strcmp(desc->block_label, "fp64") != 0 && strcmp(desc->block_label, "fp4") != 0;
+}
+
 static int load_cublaslt(struct cublaslt_api *api) {
     memset(api, 0, sizeof(*api));
     api->lib = dlopen("libcublasLt.so.13", RTLD_NOW | RTLD_LOCAL);
@@ -1222,8 +1235,7 @@ static int run_cublaslt_stress(struct cuda_api *cuda,
 
     /* Count profiles matching the filter (for deciding what to run). */
     for (size_t i = 0; i < sizeof(k_profiles) / sizeof(k_profiles[0]); i++) {
-        if (k_profiles[i].enabled && cc >= k_profiles[i].min_cc &&
-            (precision_filter == NULL || strcmp(k_profiles[i].block_label, precision_filter) == 0)) {
+        if (profile_allowed_for_run(&k_profiles[i], cc, precision_filter)) {
             planned++;
         }
     }
@@ -1240,7 +1252,7 @@ static int run_cublaslt_stress(struct cuda_api *cuda,
      * profiles matching precision_filter. */
     int planned_total = 0;
     for (size_t i = 0; i < sizeof(k_profiles) / sizeof(k_profiles[0]); i++) {
-        if (k_profiles[i].enabled && cc >= k_profiles[i].min_cc) {
+        if (profile_allowed_for_run(&k_profiles[i], cc, precision_filter)) {
             planned_total++;
         }
     }
@@ -1310,10 +1322,10 @@ static int run_cublaslt_stress(struct cuda_api *cuda,
                           desc->min_cc);
             continue;
         }
-        if (precision_filter != NULL && strcmp(desc->block_label, precision_filter) != 0) {
+        if (!profile_allowed_for_run(desc, cc, precision_filter)) {
             append_detail(report->details,
                           sizeof(report->details),
-                          "%s=SKIPPED precision_filter\n",
+                          "%s=SKIPPED benchmark_disabled\n",
                           desc->name);
             continue;
         }