How do Vue 3.6 alien signals improve reactivity performance?

Vue 3.6's "alien signals" deliver major performance improvements through fine-grained reactivity tracking on the main thread, achieving 4x faster updates and 60% lower memory usage in complex UIs. They optimize dependency collection by decoupling signal reads from effects, eliminating stale closures and reducing re-renders by 70% in dashboard applications. This trending feature makes Vue ideal for high-frequency data updates without Web Worker concurrency.

‍Example:-

Code

<script setup>
import { signal, effect } from 'vue' // Vue 3.6+

const metrics = signal({ cpu: 0, mem: 0 })
const alerts = signal([])

// Fine-grained tracking - only affected DOM updates
effect(() => {
  if (metrics.value.cpu > 90) {
    alerts.value = ['CPU overload!']  // Granular update
  }
})
</script>

<template>
  <div>CPU: {{ metrics.cpu }} {{ alerts.length ? alerts[0] : '' }}</div>
</template>