diff --git a/packages/producer/src/services/render/perfSummary.test.ts b/packages/producer/src/services/render/perfSummary.test.ts
new file mode 100644
index 000000000..257d00095
--- /dev/null
+++ b/packages/producer/src/services/render/perfSummary.test.ts
@@ -0,0 +1,45 @@
+import { describe, it, expect } from "vitest";
+import { buildRenderPerfSummary } from "./perfSummary.js";
+import type { RenderJob } from "../renderOrchestrator.js";
+
+// ponytail: minimal stub — only the fields buildRenderPerfSummary reads are real.
+const baseInput = {
+  job: { id: "r1", config: { fps: { num: 30, den: 1 }, quality: "high" } } as unknown as RenderJob,
+  workerCount: 4,
+  enableChunkedEncode: false,
+  chunkedEncodeSize: 0,
+  compositionDurationSeconds: 5,
+  totalFrames: 150,
+  outputWidth: 1920,
+  outputHeight: 1080,
+  videoCount: 0,
+  audioCount: 0,
+  totalElapsedMs: 1234,
+  perfStages: {},
+  videoExtractBreakdown: undefined,
+  tmpPeakBytes: 0,
+  captureAttempts: [],
+  hdrDiagnostics: { videoExtractionFailures: 0, imageDecodeFailures: 0 },
+  peakRssBytes: 0,
+  peakHeapUsedBytes: 0,
+};
+
+describe("buildRenderPerfSummary host telemetry", () => {
+  it("captures host facts and threads gpuDisabled through", () => {
+    const summary = buildRenderPerfSummary({ ...baseInput, gpuDisabled: true });
+    expect(summary.host).toBeDefined();
+    expect(summary.host?.gpuDisabled).toBe(true);
+    expect(summary.host?.cpuCount).toBeGreaterThan(0);
+    expect(summary.host?.totalMemMb).toBeGreaterThan(0);
+    expect(summary.host?.platform).toBe(process.platform);
+    expect(summary.host?.arch).toBe(process.arch);
+    expect(summary.host?.nodeVersion).toBe(process.version);
+  });
+
+  it("reflects gpuDisabled=false", () => {
+    const summary = buildRenderPerfSummary({ ...baseInput, gpuDisabled: false });
+    expect(summary.host?.gpuDisabled).toBe(false);
+    // workers vs cores is the headline correlation — both must be present.
+    expect(summary.workers).toBe(4);
+  });
+});
diff --git a/packages/producer/src/services/render/perfSummary.ts b/packages/producer/src/services/render/perfSummary.ts
index cce8e6971..c67b10c9b 100644
--- a/packages/producer/src/services/render/perfSummary.ts
+++ b/packages/producer/src/services/render/perfSummary.ts
@@ -3,6 +3,7 @@
  * the `perf-summary.json` debug artifact.
  */
 
+import { arch, cpus, platform, totalmem } from "node:os";
 import { fpsToNumber } from "@hyperframes/core";
 import type { CaptureCalibrationSample, CaptureCostEstimate } from "./captureCost.js";
 import type {
@@ -39,6 +40,8 @@ export function buildRenderPerfSummary(input: {
   observability?: RenderObservabilitySummary;
   peakRssBytes: number;
   peakHeapUsedBytes: number;
+  /** `cfg.disableGpu` — the hard `--disable-gpu` flag, for the `host` GPU picture. */
+  gpuDisabled: boolean;
 }): RenderPerfSummary {
   return {
     renderId: input.job.id,
@@ -82,5 +85,13 @@ export function buildRenderPerfSummary(input: {
         : undefined,
     peakRssMb: Math.round(input.peakRssBytes / (1024 * 1024)),
     peakHeapUsedMb: Math.round(input.peakHeapUsedBytes / (1024 * 1024)),
+    host: {
+      platform: platform(),
+      arch: arch(),
+      cpuCount: cpus().length,
+      totalMemMb: Math.round(totalmem() / (1024 * 1024)),
+      nodeVersion: process.version,
+      gpuDisabled: input.gpuDisabled,
+    },
   };
 }
diff --git a/packages/producer/src/services/renderOrchestrator.ts b/packages/producer/src/services/renderOrchestrator.ts
index 99137f5d4..019a36b23 100644
--- a/packages/producer/src/services/renderOrchestrator.ts
+++ b/packages/producer/src/services/renderOrchestrator.ts
@@ -326,6 +326,27 @@ export interface RenderPerfSummary {
   peakHeapUsedMb?: number;
   hdrDiagnostics?: HdrDiagnostics;
   hdrPerf?: HdrPerfSummary;
+  /**
+   * Render-host facts, captured from the orchestrator process. Lets fleet-wide
+   * telemetry correlate render performance with the machine it ran on — most
+   * importantly `cpuCount` vs the top-level `workers` (are we under-/over-
+   * subscribing cores?) and `totalMemMb` (does `lowMemoryMode` / single-worker
+   * collapse track real memory pressure?). `gpuDisabled` completes the GPU
+   * picture alongside `observability.browserGpuMode`.
+   *
+   * Reflects the ORCHESTRATOR host. For distributed renders the chunk workers
+   * may run on different machines; this is still the right signal for the
+   * common single-machine render. Optional for back-compat with serialized
+   * older summaries.
+   */
+  host?: {
+    platform: string;
+    arch: string;
+    cpuCount: number;
+    totalMemMb: number;
+    nodeVersion: string;
+    gpuDisabled: boolean;
+  };
 }
 
 export interface HdrDiagnostics {
@@ -1639,6 +1660,7 @@ export async function executeRenderJob(
       observability: observabilitySummary,
       peakRssBytes: memSampler.peakRssBytes(),
       peakHeapUsedBytes: memSampler.peakHeapUsedBytes(),
+      gpuDisabled: cfg.disableGpu,
     });
     job.perfSummary = perfSummary;
     if (job.config.debug) {