Add ramp-up mode to NVIDIA GPU benchmark

Adds a new checkbox (enabled by default) in the benchmark section.
In ramp-up mode N tasks are spawned simultaneously: 1 GPU, then 2,
then 3, up to all selected GPUs — each step runs its GPUs in parallel.
NCCL runs only on the final step.

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

audit/internal/platform/benchmark.go

@@ -121,15 +121,22 @@ func (s *System) RunNvidiaBenchmark(ctx context.Context, baseDir string, opts Nv
 	var serverIdleOK, serverLoadedOK bool
 	var serverLoadedSamples int
 
+	// Run nvidia-smi -q first: used both for the log file and as a fallback
+	// source of max clock values when CSV clock fields are unsupported.
+	var nvsmiQOut []byte
+	if out, err := runSATCommandCtx(ctx, verboseLog, "00-nvidia-smi-q.log", []string{"nvidia-smi", "-q"}, nil, nil); err == nil {
+		nvsmiQOut = out
+		_ = os.WriteFile(filepath.Join(runDir, "00-nvidia-smi-q.log"), out, 0644)
+	}
+
 	infoByIndex, infoErr := queryBenchmarkGPUInfo(selected)
 	if infoErr != nil {
 		result.Warnings = append(result.Warnings, "gpu inventory query failed: "+infoErr.Error())
 		result.Normalization.Status = "partial"
 	}
-
-	if out, err := runSATCommandCtx(ctx, verboseLog, "00-nvidia-smi-q.log", []string{"nvidia-smi", "-q"}, nil, nil); err == nil {
-		_ = os.WriteFile(filepath.Join(runDir, "00-nvidia-smi-q.log"), out, 0644)
-	}
+	// Enrich with max clocks from verbose output — covers GPUs where
+	// clocks.max.* CSV fields are unsupported (e.g. Blackwell / driver 98.x).
+	enrichGPUInfoWithMaxClocks(infoByIndex, nvsmiQOut)
 
 	activeApps, err := queryActiveComputeApps(selected)
 	if err == nil && len(activeApps) > 0 {
@@ -370,9 +377,13 @@ func resolveBenchmarkProfile(profile string) benchmarkProfileSpec {
 // Fields are tried in order; the first successful query wins. Extended fields
 // (attribute.multiprocessor_count, power.default_limit) are not supported on
 // all driver versions, so we fall back to the base set if the full query fails.
+// The minimal fallback omits clock fields entirely — clocks.max.* returns
+// exit status 2 on some GPU generations (e.g. Blackwell); max clocks are
+// then recovered from nvidia-smi -q via enrichGPUInfoWithMaxClocks.
 var benchmarkGPUInfoQueries = []struct {
 	fields   string
 	extended bool // whether this query includes optional extended fields
+	minimal  bool // clock fields omitted; max clocks must be filled separately
 }{
 	{
 		fields:   "index,uuid,name,pci.bus_id,vbios_version,power.limit,clocks.max.graphics,clocks.max.memory,clocks.base.graphics,attribute.multiprocessor_count,power.default_limit",
@@ -382,6 +393,83 @@ var benchmarkGPUInfoQueries = []struct {
 		fields:   "index,uuid,name,pci.bus_id,vbios_version,power.limit,clocks.max.graphics,clocks.max.memory,clocks.base.graphics",
 		extended: false,
 	},
+	{
+		fields:  "index,uuid,name,pci.bus_id,vbios_version,power.limit",
+		minimal: true,
+	},
+}
+
+// enrichGPUInfoWithMaxClocks fills MaxGraphicsClockMHz / MaxMemoryClockMHz for
+// any GPU in infoByIndex where those values are still zero.  It parses the
+// "Max Clocks" section of nvidia-smi -q output (already available as nvsmiQ).
+// This is the fallback for GPUs (e.g. Blackwell) where clocks.max.* CSV fields
+// return exit status 2 but the verbose query works fine.
+func enrichGPUInfoWithMaxClocks(infoByIndex map[int]benchmarkGPUInfo, nvsmiQ []byte) {
+	if len(infoByIndex) == 0 || len(nvsmiQ) == 0 {
+		return
+	}
+
+	// Build bus_id → index map for matching verbose sections to GPU indices.
+	busToBenchIdx := make(map[string]int, len(infoByIndex))
+	for idx, info := range infoByIndex {
+		if info.BusID != "" {
+			// nvidia-smi -q uses "GPU 00000000:4E:00.0" (8-digit domain),
+			// while --query-gpu returns the same format; normalise to lower.
+			busToBenchIdx[strings.ToLower(strings.TrimSpace(info.BusID))] = idx
+		}
+	}
+
+	// Split the verbose output into per-GPU sections on "^GPU " lines.
+	gpuSectionRe := regexp.MustCompile(`(?m)^GPU\s+([\dA-Fa-f:\.]+)`)
+	maxGfxRe := regexp.MustCompile(`(?i)Max Clocks[\s\S]*?Graphics\s*:\s*(\d+)\s*MHz`)
+	maxMemRe := regexp.MustCompile(`(?i)Max Clocks[\s\S]*?Memory\s*:\s*(\d+)\s*MHz`)
+
+	sectionStarts := gpuSectionRe.FindAllSubmatchIndex(nvsmiQ, -1)
+	for i, loc := range sectionStarts {
+		busID := strings.ToLower(string(nvsmiQ[loc[2]:loc[3]]))
+		benchIdx, ok := busToBenchIdx[busID]
+		if !ok {
+			// Bus IDs from verbose output may have a different domain prefix;
+			// try suffix match on the slot portion (XX:XX.X).
+			for k, v := range busToBenchIdx {
+				if strings.HasSuffix(k, busID) || strings.HasSuffix(busID, k) {
+					benchIdx = v
+					ok = true
+					break
+				}
+			}
+		}
+		if !ok {
+			continue
+		}
+
+		info := infoByIndex[benchIdx]
+		if info.MaxGraphicsClockMHz > 0 && info.MaxMemoryClockMHz > 0 {
+			continue // already populated
+		}
+
+		end := len(nvsmiQ)
+		if i+1 < len(sectionStarts) {
+			end = sectionStarts[i+1][0]
+		}
+		section := nvsmiQ[loc[0]:end]
+
+		if info.MaxGraphicsClockMHz == 0 {
+			if m := maxGfxRe.FindSubmatch(section); m != nil {
+				if v, err := strconv.ParseFloat(string(m[1]), 64); err == nil {
+					info.MaxGraphicsClockMHz = v
+				}
+			}
+		}
+		if info.MaxMemoryClockMHz == 0 {
+			if m := maxMemRe.FindSubmatch(section); m != nil {
+				if v, err := strconv.ParseFloat(string(m[1]), 64); err == nil {
+					info.MaxMemoryClockMHz = v
+				}
+			}
+		}
+		infoByIndex[benchIdx] = info
+	}
 }
 
 func queryBenchmarkGPUInfo(gpuIndices []int) (map[int]benchmarkGPUInfo, error) {
@@ -409,9 +497,13 @@ func queryBenchmarkGPUInfo(gpuIndices []int) (map[int]benchmarkGPUInfo, error) {
 			continue
 		}
 
+		minFields := 6
+		if !q.minimal {
+			minFields = 9
+		}
 		infoByIndex := make(map[int]benchmarkGPUInfo, len(rows))
 		for _, row := range rows {
-			if len(row) < 9 {
+			if len(row) < minFields {
 				continue
 			}
 			idx, err := strconv.Atoi(strings.TrimSpace(row[0]))
@@ -419,24 +511,26 @@ func queryBenchmarkGPUInfo(gpuIndices []int) (map[int]benchmarkGPUInfo, error) {
 				continue
 			}
 			info := benchmarkGPUInfo{
-				Index:               idx,
-				UUID:                strings.TrimSpace(row[1]),
-				Name:                strings.TrimSpace(row[2]),
-				BusID:               strings.TrimSpace(row[3]),
-				VBIOS:               strings.TrimSpace(row[4]),
-				PowerLimitW:         parseBenchmarkFloat(row[5]),
-				MaxGraphicsClockMHz: parseBenchmarkFloat(row[6]),
-				MaxMemoryClockMHz:   parseBenchmarkFloat(row[7]),
+				Index:       idx,
+				UUID:        strings.TrimSpace(row[1]),
+				Name:        strings.TrimSpace(row[2]),
+				BusID:       strings.TrimSpace(row[3]),
+				VBIOS:       strings.TrimSpace(row[4]),
+				PowerLimitW: parseBenchmarkFloat(row[5]),
 			}
-			if len(row) >= 9 {
-				info.BaseGraphicsClockMHz = parseBenchmarkFloat(row[8])
-			}
-			if q.extended {
-				if len(row) >= 10 {
-					info.MultiprocessorCount = int(parseBenchmarkFloat(row[9]))
+			if !q.minimal {
+				info.MaxGraphicsClockMHz = parseBenchmarkFloat(row[6])
+				info.MaxMemoryClockMHz = parseBenchmarkFloat(row[7])
+				if len(row) >= 9 {
+					info.BaseGraphicsClockMHz = parseBenchmarkFloat(row[8])
 				}
-				if len(row) >= 11 {
-					info.DefaultPowerLimitW = parseBenchmarkFloat(row[10])
+				if q.extended {
+					if len(row) >= 10 {
+						info.MultiprocessorCount = int(parseBenchmarkFloat(row[9]))
+					}
+					if len(row) >= 11 {
+						info.DefaultPowerLimitW = parseBenchmarkFloat(row[10])
+					}
 				}
 			}
 			infoByIndex[idx] = info

audit/internal/platform/benchmark_test.go

@@ -178,3 +178,67 @@ func TestRenderBenchmarkReportIncludesTerminalChartsWithoutANSI(t *testing.T) {
 		t.Fatalf("report should not contain ANSI escapes\n%s", report)
 	}
 }
+
+func TestEnrichGPUInfoWithMaxClocks(t *testing.T) {
+	t.Parallel()
+
+	nvsmiQ := []byte(`
+GPU 00000000:4E:00.0
+    Product Name                          : NVIDIA RTX PRO 6000 Blackwell Server Edition
+    Clocks
+        Graphics                          : 2422 MHz
+        Memory                            : 12481 MHz
+    Max Clocks
+        Graphics                          : 2430 MHz
+        SM                                : 2430 MHz
+        Memory                            : 12481 MHz
+        Video                             : 2107 MHz
+
+GPU 00000000:4F:00.0
+    Product Name                          : NVIDIA RTX PRO 6000 Blackwell Server Edition
+    Max Clocks
+        Graphics                          : 2430 MHz
+        Memory                            : 12481 MHz
+`)
+
+	infoByIndex := map[int]benchmarkGPUInfo{
+		0: {Index: 0, BusID: "00000000:4E:00.0"},
+		1: {Index: 1, BusID: "00000000:4F:00.0"},
+	}
+
+	enrichGPUInfoWithMaxClocks(infoByIndex, nvsmiQ)
+
+	if infoByIndex[0].MaxGraphicsClockMHz != 2430 {
+		t.Errorf("GPU 0 MaxGraphicsClockMHz = %v, want 2430", infoByIndex[0].MaxGraphicsClockMHz)
+	}
+	if infoByIndex[0].MaxMemoryClockMHz != 12481 {
+		t.Errorf("GPU 0 MaxMemoryClockMHz = %v, want 12481", infoByIndex[0].MaxMemoryClockMHz)
+	}
+	if infoByIndex[1].MaxGraphicsClockMHz != 2430 {
+		t.Errorf("GPU 1 MaxGraphicsClockMHz = %v, want 2430", infoByIndex[1].MaxGraphicsClockMHz)
+	}
+	if infoByIndex[1].MaxMemoryClockMHz != 12481 {
+		t.Errorf("GPU 1 MaxMemoryClockMHz = %v, want 12481", infoByIndex[1].MaxMemoryClockMHz)
+	}
+}
+
+func TestEnrichGPUInfoWithMaxClocksSkipsPopulated(t *testing.T) {
+	t.Parallel()
+
+	nvsmiQ := []byte(`
+GPU 00000000:4E:00.0
+    Max Clocks
+        Graphics                          : 9999 MHz
+        Memory                            : 9999 MHz
+`)
+	// Already populated — must not be overwritten.
+	infoByIndex := map[int]benchmarkGPUInfo{
+		0: {Index: 0, BusID: "00000000:4E:00.0", MaxGraphicsClockMHz: 2430, MaxMemoryClockMHz: 12481},
+	}
+
+	enrichGPUInfoWithMaxClocks(infoByIndex, nvsmiQ)
+
+	if infoByIndex[0].MaxGraphicsClockMHz != 2430 {
+		t.Errorf("expected existing value to be preserved, got %v", infoByIndex[0].MaxGraphicsClockMHz)
+	}
+}

audit/internal/webui/api.go

@@ -12,6 +12,7 @@ import (
 	"path/filepath"
 	"regexp"
 	"sort"
+	"strconv"
 	"strings"
 	"sync/atomic"
 	"syscall"
@@ -209,6 +210,14 @@ func joinTaskIndices(indices []int) string {
 	return strings.Join(parts, ",")
 }
 
+func formatGPUIndexList(indices []int) string {
+	parts := make([]string, len(indices))
+	for i, idx := range indices {
+		parts[i] = strconv.Itoa(idx)
+	}
+	return strings.Join(parts, ",")
+}
+
 func formatSplitTaskName(baseName, selectionLabel string) string {
 	baseName = strings.TrimSpace(baseName)
 	selectionLabel = strings.TrimSpace(selectionLabel)
@@ -540,6 +549,7 @@ func (h *handler) handleAPIBenchmarkNvidiaRun(w http.ResponseWriter, r *http.Req
 		ExcludeGPUIndices []int  `json:"exclude_gpu_indices"`
 		RunNCCL           *bool  `json:"run_nccl"`
 		ParallelGPUs      *bool  `json:"parallel_gpus"`
+		RampUp            *bool  `json:"ramp_up"`
 		DisplayName       string `json:"display_name"`
 	}
 	if r.Body != nil {
@@ -557,10 +567,63 @@ func (h *handler) handleAPIBenchmarkNvidiaRun(w http.ResponseWriter, r *http.Req
 	if body.ParallelGPUs != nil {
 		parallelGPUs = *body.ParallelGPUs
 	}
+	rampUp := false
+	if body.RampUp != nil {
+		rampUp = *body.RampUp
+	}
 	name := taskDisplayName("nvidia-benchmark", "", "")
 	if strings.TrimSpace(body.DisplayName) != "" {
 		name = body.DisplayName
 	}
+
+	if rampUp && len(body.GPUIndices) > 1 {
+		// Ramp-up mode: resolve GPU list, then create one task per prefix
+		// [gpu0], [gpu0,gpu1], ..., [gpu0,...,gpuN-1], each running in parallel.
+		gpus, err := apiListNvidiaGPUs(h.opts.App)
+		if err != nil {
+			writeError(w, http.StatusBadRequest, err.Error())
+			return
+		}
+		resolved, err := expandSelectedGPUIndices(gpus, body.GPUIndices, body.ExcludeGPUIndices)
+		if err != nil {
+			writeError(w, http.StatusBadRequest, err.Error())
+			return
+		}
+		if len(resolved) < 2 {
+			// Fall through to normal single-task path.
+			rampUp = false
+		} else {
+			now := time.Now()
+			var allTasks []*Task
+			for step := 1; step <= len(resolved); step++ {
+				subset := resolved[:step]
+				stepName := fmt.Sprintf("%s [ramp %d/%d: GPU %s]", name, step, len(resolved), formatGPUIndexList(subset))
+				t := &Task{
+					ID:        newJobID("benchmark-nvidia"),
+					Name:      stepName,
+					Target:    "nvidia-benchmark",
+					Priority:  15,
+					Status:    TaskPending,
+					CreatedAt: now,
+					params: taskParams{
+						GPUIndices:       append([]int(nil), subset...),
+						SizeMB:           body.SizeMB,
+						BenchmarkProfile: body.Profile,
+						RunNCCL:          runNCCL && step == len(resolved),
+						ParallelGPUs:     true,
+						DisplayName:      stepName,
+					},
+				}
+				allTasks = append(allTasks, t)
+			}
+			for _, t := range allTasks {
+				globalQueue.enqueue(t)
+			}
+			writeTaskRunResponse(w, allTasks)
+			return
+		}
+	}
+
 	tasks, err := buildNvidiaTaskSet("nvidia-benchmark", 15, time.Now(), taskParams{
 		GPUIndices:        body.GPUIndices,
 		ExcludeGPUIndices: body.ExcludeGPUIndices,

audit/internal/webui/pages.go

@@ -1342,11 +1342,11 @@ func renderValidate(opts HandlerOptions) string {
 
 <div class="grid3">
 ` + renderSATCard("nvidia", "NVIDIA GPU", "runNvidiaValidateSet('nvidia')", "", renderValidateCardBody(
-			inv.NVIDIA,
-			`Runs NVIDIA diagnostics and board inventory checks.`,
-			`<code>nvidia-smi</code>, <code>dmidecode</code>, <code>dcgmi diag</code>`,
-			`Level 2 in Validate, Level 3 in Stress. Runs one GPU at a time on the selected NVIDIA GPUs.`,
-		)) +
+		inv.NVIDIA,
+		`Runs NVIDIA diagnostics and board inventory checks.`,
+		`<code>nvidia-smi</code>, <code>dmidecode</code>, <code>dcgmi diag</code>`,
+		`Level 2 in Validate, Level 3 in Stress. Runs one GPU at a time on the selected NVIDIA GPUs.`,
+	)) +
 		`<div id="sat-card-nvidia-targeted-stress">` +
 		renderSATCard("nvidia-targeted-stress", "NVIDIA GPU Targeted Stress", "runNvidiaValidateSet('nvidia-targeted-stress')", "", renderValidateCardBody(
 			inv.NVIDIA,
@@ -1966,9 +1966,13 @@ func renderBenchmark(opts HandlerOptions) string {
           <p style="color:var(--muted);font-size:13px">Loading NVIDIA GPUs...</p>
         </div>
       </div>
+      <label class="benchmark-cb-row">
+        <input type="checkbox" id="benchmark-ramp-up" checked onchange="benchmarkUpdateSelectionNote()">
+        <span>Ramp-up mode: run 1 GPU, then 2, then 3… up to all selected GPUs (each step is a separate task)</span>
+      </label>
       <label class="benchmark-cb-row">
         <input type="checkbox" id="benchmark-parallel-gpus">
-        <span>Run all selected GPUs simultaneously (parallel mode)</span>
+        <span>Run all selected GPUs simultaneously (parallel mode, ignored in ramp-up)</span>
       </label>
       <label class="benchmark-cb-row">
         <input type="checkbox" id="benchmark-run-nccl" checked>
@@ -2036,11 +2040,16 @@ function benchmarkUpdateSelectionNote() {
     return;
   }
   btn.disabled = false;
-  note.textContent = 'Selected GPUs: ' + selected.join(', ') + '.';
-  if (nccl && nccl.checked && selected.length < 2) {
-    note.textContent += ' NCCL will be skipped because fewer than 2 GPUs are selected.';
-  } else if (nccl && nccl.checked) {
-    note.textContent += ' NCCL interconnect will use only these GPUs.';
+  const rampUp = selected.length > 1 && !!document.getElementById('benchmark-ramp-up').checked;
+  if (rampUp) {
+    note.textContent = 'Ramp-up: will spawn ' + selected.length + ' tasks (1 GPU → ' + selected.length + ' GPUs). NCCL runs on the final step only.';
+  } else {
+    note.textContent = 'Selected GPUs: ' + selected.join(', ') + '.';
+    if (nccl && nccl.checked && selected.length < 2) {
+      note.textContent += ' NCCL will be skipped because fewer than 2 GPUs are selected.';
+    } else if (nccl && nccl.checked) {
+      note.textContent += ' NCCL interconnect will use only these GPUs.';
+    }
   }
 }
 
@@ -2095,12 +2104,14 @@ function runNvidiaBenchmark() {
     return;
   }
   if (benchmarkES) { benchmarkES.close(); benchmarkES = null; }
-  const parallelGPUs = !!document.getElementById('benchmark-parallel-gpus').checked;
+  const rampUp = selected.length > 1 && !!document.getElementById('benchmark-ramp-up').checked;
+  const parallelGPUs = !rampUp && !!document.getElementById('benchmark-parallel-gpus').checked;
   const body = {
     profile: document.getElementById('benchmark-profile').value || 'standard',
     gpu_indices: selected,
     run_nccl: !!document.getElementById('benchmark-run-nccl').checked,
     parallel_gpus: parallelGPUs,
+    ramp_up: rampUp,
     display_name: 'NVIDIA Benchmark'
   };
   document.getElementById('benchmark-output').style.display = 'block';
@@ -2373,7 +2384,7 @@ func renderBurn() string {
 	    <p id="burn-selection-note" style="font-size:12px;color:var(--muted);margin:10px 0 0">Select at least one NVIDIA GPU to enable NVIDIA burn recipes.</p>
 	    <label class="cb-row" style="margin-top:10px">
 	      <input type="checkbox" id="burn-stagger-nvidia">
-	      <span>Ramp selected NVIDIA GPUs one by one before full-load hold. Uses a 3-minute stabilization window per GPU, then keeps all selected GPUs under load for the chosen Burn Profile duration.</span>
+	      <span>Ramp selected NVIDIA GPUs one by one before the full-load hold. Smoke: +2 min per GPU, then 5 min with all selected GPUs under load. Acceptance: +10 min per GPU, then at least 1 hour with all selected GPUs under load. Overnight: +1 hour per GPU, then at least 1 hour with all selected GPUs under load, capped at 10 hours total.</span>
 	    </label>
 	  </div>
 	</div>
@@ -3108,7 +3119,6 @@ usbRefresh();
 </script>`
 }
 
-
 func renderNvidiaSelfHealInline() string {
 	return `<p style="font-size:13px;color:var(--muted);margin-bottom:12px">Inspect NVIDIA GPU health, restart the bee-nvidia driver service, and issue a per-GPU reset when the driver reports reset required.</p>
 <div style="display:flex;gap:8px;flex-wrap:wrap;margin-bottom:12px">

audit/internal/webui/tasks.go

@@ -152,6 +152,12 @@ type burnPreset struct {
 	DurationSec int
 }
 
+type nvidiaRampSpec struct {
+	DurationSec      int
+	StaggerSeconds   int
+	TotalDurationSec int
+}
+
 func resolveBurnPreset(profile string) burnPreset {
 	switch profile {
 	case "overnight":
@@ -163,11 +169,43 @@ func resolveBurnPreset(profile string) burnPreset {
 	}
 }
 
-func boolToNvidiaStaggerSeconds(enabled bool, selected []int) int {
-	if enabled && len(selected) > 1 {
-		return 180
+func resolveNvidiaRampPlan(profile string, enabled bool, selected []int) (nvidiaRampSpec, error) {
+	base := resolveBurnPreset(profile).DurationSec
+	plan := nvidiaRampSpec{
+		DurationSec:      base,
+		TotalDurationSec: base,
 	}
-	return 0
+	if !enabled {
+		return plan, nil
+	}
+	count := len(selected)
+	if count == 0 {
+		return nvidiaRampSpec{}, fmt.Errorf("staggered NVIDIA burn requires explicit GPU selection")
+	}
+	if count == 1 {
+		return plan, nil
+	}
+
+	switch profile {
+	case "acceptance":
+		plan.StaggerSeconds = 10 * 60
+		plan.TotalDurationSec = plan.DurationSec + plan.StaggerSeconds*(count-1)
+	case "overnight":
+		plan.StaggerSeconds = 60 * 60
+		plan.TotalDurationSec = 8 * 60 * 60
+		minTotal := count * 60 * 60
+		if plan.TotalDurationSec < minTotal {
+			plan.TotalDurationSec = minTotal
+		}
+		if plan.TotalDurationSec > 10*60*60 {
+			return nvidiaRampSpec{}, fmt.Errorf("overnight staggered NVIDIA burn supports at most 10 GPUs")
+		}
+		plan.DurationSec = plan.TotalDurationSec - plan.StaggerSeconds*(count-1)
+	default:
+		plan.StaggerSeconds = 2 * 60
+		plan.TotalDurationSec = plan.DurationSec + plan.StaggerSeconds*(count-1)
+	}
+	return plan, nil
 }
 
 func resolvePlatformStressPreset(profile string) platform.PlatformStressOptions {
@@ -600,7 +638,7 @@ func (q *taskQueue) runTask(t *Task, j *jobState, ctx context.Context) {
 			RunNCCL:           t.params.RunNCCL,
 			ParallelGPUs:      t.params.ParallelGPUs,
 		}, j.append)
-		case "nvidia-compute":
+	case "nvidia-compute":
 		if a == nil {
 			err = fmt.Errorf("app not configured")
 			break
@@ -609,11 +647,18 @@ func (q *taskQueue) runTask(t *Task, j *jobState, ctx context.Context) {
 		if t.params.BurnProfile != "" && dur <= 0 {
 			dur = resolveBurnPreset(t.params.BurnProfile).DurationSec
 		}
-			staggerSec := boolToNvidiaStaggerSeconds(t.params.StaggerGPUStart, t.params.GPUIndices)
-			if staggerSec > 0 {
-				j.append(fmt.Sprintf("NVIDIA staggered ramp-up enabled: %ds per GPU", staggerSec))
-			}
-			archive, err = a.RunNvidiaOfficialComputePack(ctx, "", dur, t.params.GPUIndices, staggerSec, j.append)
+		rampPlan, planErr := resolveNvidiaRampPlan(t.params.BurnProfile, t.params.StaggerGPUStart, t.params.GPUIndices)
+		if planErr != nil {
+			err = planErr
+			break
+		}
+		if t.params.BurnProfile != "" && t.params.StaggerGPUStart && dur <= 0 {
+			dur = rampPlan.DurationSec
+		}
+		if rampPlan.StaggerSeconds > 0 {
+			j.append(fmt.Sprintf("NVIDIA staggered ramp-up enabled: %ds per GPU; post-ramp hold: %ds; total runtime: %ds", rampPlan.StaggerSeconds, dur, rampPlan.TotalDurationSec))
+		}
+		archive, err = a.RunNvidiaOfficialComputePack(ctx, "", dur, t.params.GPUIndices, rampPlan.StaggerSeconds, j.append)
 	case "nvidia-targeted-power":
 		if a == nil {
 			err = fmt.Errorf("app not configured")
@@ -663,13 +708,24 @@ func (q *taskQueue) runTask(t *Task, j *jobState, ctx context.Context) {
 		if t.params.BurnProfile != "" && dur <= 0 {
 			dur = resolveBurnPreset(t.params.BurnProfile).DurationSec
 		}
-			archive, err = runNvidiaStressPackCtx(a, ctx, "", platform.NvidiaStressOptions{
-				DurationSec:       dur,
-				Loader:            t.params.Loader,
-				GPUIndices:        t.params.GPUIndices,
-				ExcludeGPUIndices: t.params.ExcludeGPUIndices,
-				StaggerSeconds:    boolToNvidiaStaggerSeconds(t.params.StaggerGPUStart, t.params.GPUIndices),
-			}, j.append)
+		rampPlan, planErr := resolveNvidiaRampPlan(t.params.BurnProfile, t.params.StaggerGPUStart, t.params.GPUIndices)
+		if planErr != nil {
+			err = planErr
+			break
+		}
+		if t.params.BurnProfile != "" && t.params.StaggerGPUStart && dur <= 0 {
+			dur = rampPlan.DurationSec
+		}
+		if rampPlan.StaggerSeconds > 0 {
+			j.append(fmt.Sprintf("NVIDIA staggered ramp-up enabled: %ds per GPU; post-ramp hold: %ds; total runtime: %ds", rampPlan.StaggerSeconds, dur, rampPlan.TotalDurationSec))
+		}
+		archive, err = runNvidiaStressPackCtx(a, ctx, "", platform.NvidiaStressOptions{
+			DurationSec:       dur,
+			Loader:            t.params.Loader,
+			GPUIndices:        t.params.GPUIndices,
+			ExcludeGPUIndices: t.params.ExcludeGPUIndices,
+			StaggerSeconds:    rampPlan.StaggerSeconds,
+		}, j.append)
 	case "memory":
 		if a == nil {
 			err = fmt.Errorf("app not configured")

audit/internal/webui/tasks_test.go

@@ -491,6 +491,83 @@ func TestResolveBurnPreset(t *testing.T) {
 	}
 }
 
+func TestResolveNvidiaRampPlan(t *testing.T) {
+	tests := []struct {
+		name     string
+		profile  string
+		enabled  bool
+		selected []int
+		want     nvidiaRampSpec
+		wantErr  string
+	}{
+		{
+			name:     "disabled uses base preset",
+			profile:  "acceptance",
+			selected: []int{0, 1},
+			want:     nvidiaRampSpec{DurationSec: 60 * 60, TotalDurationSec: 60 * 60},
+		},
+		{
+			name:     "smoke ramp uses two minute steps",
+			profile:  "smoke",
+			enabled:  true,
+			selected: []int{0, 1, 2},
+			want:     nvidiaRampSpec{DurationSec: 5 * 60, StaggerSeconds: 2 * 60, TotalDurationSec: 9 * 60},
+		},
+		{
+			name:     "acceptance ramp uses ten minute steps",
+			profile:  "acceptance",
+			enabled:  true,
+			selected: []int{0, 1, 2},
+			want:     nvidiaRampSpec{DurationSec: 60 * 60, StaggerSeconds: 10 * 60, TotalDurationSec: 80 * 60},
+		},
+		{
+			name:     "overnight stays at eight hours when possible",
+			profile:  "overnight",
+			enabled:  true,
+			selected: []int{0, 1, 2},
+			want:     nvidiaRampSpec{DurationSec: 6 * 60 * 60, StaggerSeconds: 60 * 60, TotalDurationSec: 8 * 60 * 60},
+		},
+		{
+			name:     "overnight extends to keep one hour after final gpu",
+			profile:  "overnight",
+			enabled:  true,
+			selected: []int{0, 1, 2, 3, 4, 5, 6, 7, 8},
+			want:     nvidiaRampSpec{DurationSec: 60 * 60, StaggerSeconds: 60 * 60, TotalDurationSec: 9 * 60 * 60},
+		},
+		{
+			name:     "overnight rejects impossible gpu count",
+			profile:  "overnight",
+			enabled:  true,
+			selected: []int{0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10},
+			wantErr:  "at most 10 GPUs",
+		},
+		{
+			name:    "enabled requires explicit selection",
+			profile: "smoke",
+			enabled: true,
+			wantErr: "requires explicit GPU selection",
+		},
+	}
+
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			got, err := resolveNvidiaRampPlan(tc.profile, tc.enabled, tc.selected)
+			if tc.wantErr != "" {
+				if err == nil || !strings.Contains(err.Error(), tc.wantErr) {
+					t.Fatalf("err=%v want substring %q", err, tc.wantErr)
+				}
+				return
+			}
+			if err != nil {
+				t.Fatalf("resolveNvidiaRampPlan error: %v", err)
+			}
+			if got != tc.want {
+				t.Fatalf("resolveNvidiaRampPlan(%q, %t, %v)=%+v want %+v", tc.profile, tc.enabled, tc.selected, got, tc.want)
+			}
+		})
+	}
+}
+
 func TestTaskDisplayNameUsesNvidiaStressLoader(t *testing.T) {
 	tests := []struct {
 		loader string