From c8ed90fa217dfed921879c627fff0586326607c5 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Miguel=20=C3=81ngel?= <miguel.sierra@heygen.com>
Date: Mon, 25 May 2026 19:13:00 +0000
Subject: [PATCH] fix(engine): use totalmem() instead of freemem() for memory
 scaling

Addresses review feedback: freemem() is misleading on macOS where
aggressive file caching reports low free memory even on high-spec
machines. Switched to totalmem()-based thresholds consistent with
calculateOptimalWorkers in parallelCoordinator.ts.

Thresholds now based on total RAM:
- <4GB total: GPU=512MB, V8=256MB, cache=32/128MB
- <8GB total: GPU=1024MB, V8=512MB, cache=64/256MB
- >=8GB total: unchanged (4096MB GPU, no V8 cap, 256/1500MB cache)
---
 packages/engine/src/config.ts                 | 19 +++++++++----------
 .../engine/src/services/browserManager.ts     | 18 +++++++++---------
 2 files changed, 18 insertions(+), 19 deletions(-)

diff --git a/packages/engine/src/config.ts b/packages/engine/src/config.ts
index 5bc4c5e93..84c13dfde 100644
--- a/packages/engine/src/config.ts
+++ b/packages/engine/src/config.ts
@@ -208,26 +208,25 @@ export const DEFAULT_CONFIG: EngineConfig = {
   debug: false,
 };
 
-function getSystemFreeMb(): number {
+function getSystemTotalMb(): number {
   try {
-    const { freemem } = require("os") as typeof import("os");
-    return Math.floor(freemem() / (1024 * 1024));
+    return Math.floor(require("os").totalmem() / (1024 * 1024));
   } catch {
-    return 8192;
+    return 16384;
   }
 }
 
 function memoryAdaptiveCacheLimit(): number {
-  const free = getSystemFreeMb();
-  if (free < 2048) return 32;
-  if (free < 4096) return 64;
+  const total = getSystemTotalMb();
+  if (total < 4096) return 32;
+  if (total < 8192) return 64;
   return DEFAULT_CONFIG.frameDataUriCacheLimit;
 }
 
 function memoryAdaptiveCacheBytesMb(): number {
-  const free = getSystemFreeMb();
-  if (free < 2048) return 128;
-  if (free < 4096) return 256;
+  const total = getSystemTotalMb();
+  if (total < 4096) return 128;
+  if (total < 8192) return 256;
   return DEFAULT_CONFIG.frameDataUriCacheBytesLimitMb;
 }
 
diff --git a/packages/engine/src/services/browserManager.ts b/packages/engine/src/services/browserManager.ts
index 0f9cae2c7..9dae7469c 100644
--- a/packages/engine/src/services/browserManager.ts
+++ b/packages/engine/src/services/browserManager.ts
@@ -8,7 +8,7 @@
 import type { Browser, PuppeteerNode } from "puppeteer-core";
 import { existsSync, readdirSync } from "fs";
 import { join } from "path";
-import { freemem, homedir } from "os";
+import { homedir, totalmem } from "os";
 import { DEFAULT_CONFIG, type EngineConfig } from "../config.js";
 
 let _puppeteer: PuppeteerNode | undefined;
@@ -476,21 +476,21 @@ export function _setPuppeteerForTests(mock: PuppeteerNode | undefined): void {
   _puppeteer = mock;
 }
 
-function getFreeMb(): number {
-  return Math.floor(freemem() / (1024 * 1024));
+function getTotalMemMb(): number {
+  return Math.floor(totalmem() / (1024 * 1024));
 }
 
 function getGpuMemBudgetMb(): number {
-  const free = getFreeMb();
-  if (free < 2048) return 512;
-  if (free < 4096) return 1024;
+  const total = getTotalMemMb();
+  if (total < 4096) return 512;
+  if (total < 8192) return 1024;
   return 4096;
 }
 
 function getLowMemoryFlags(): string[] {
-  const free = getFreeMb();
-  if (free >= 4096) return [];
-  const heapMb = free < 2048 ? 256 : 512;
+  const total = getTotalMemMb();
+  if (total >= 8192) return [];
+  const heapMb = total < 4096 ? 256 : 512;
   return [`--js-flags=--max-old-space-size=${heapMb}`];
 }