.NET Garbage Collection: Server GC vs Workstation GC

📌 What Are the GC Modes in .NET?

.NET supports two primary modes of garbage collection:

• Workstation GC – Optimized for desktop applications and user-interactive scenarios.

• Server GC – Designed for high-throughput, scalable applications that run on server-grade hardware.

⚙️ Workstation GC

Workstation GC is the default mode when running .NET apps in an interactive environment (like on a developer's machine). It prioritizes low-latency collection to minimize interruptions in UI responsiveness.

• ✅ Lower latency, ideal for UI apps

• ✅ Lightweight, single-threaded collections (unless concurrent GC is enabled)

• ❌ Sub-optimal for multi-core environments and background server workloads

🚀 Server GC

Server GC, on the other hand, is designed for backend services, APIs, and compute-intensive workloads. It runs in a multi-threaded, parallel fashion, scaling effectively with the number of cores available.

• ✅ Parallel collection for better throughput

• ✅ Separate GC heap per logical core

• ✅ Ideal for high-load web APIs, background workers, and microservices

• ❌ Higher memory overhead due to per-core GC heaps

• ❌ May introduce longer pauses (stop-the-world) in some workloads

🐳 Which is Better for Containers and Kubernetes?

When running applications inside containers — especially in environments like Kubernetes — you are typically aiming for:

• ➡️ High throughput

• ➡️ Efficient use of allocated CPU cores

• ➡️ Scalability across pods and nodes

Server GC aligns well with these goals because it takes advantage of multi-core systems and performs collections in parallel. Even in single-container-per-core setups, Server GC can outperform Workstation GC due to its design philosophy of maximizing server resource utilization.

📄 Enabling Server GC

You can opt into Server GC explicitly using your application’s runtimeconfig.json or .csproj file:

// runtimeconfig.template.json
{
  "configProperties": {
    "System.GC.Server": true
  }
}

Or in .csproj:

<PropertyGroup>
  <ServerGarbageCollection>true</ServerGarbageCollection>
</PropertyGroup>

🔍 Final Thoughts

In containerized and orchestrated environments, you typically want predictable, high-throughput performance. Server GC is the preferred choice in almost all production deployment scenarios unless your app has very specific memory or responsiveness constraints.

Understanding and configuring the right GC mode is a small but impactful step toward optimizing your .NET app for modern, distributed systems.

📚 Further Reading

• .NET GC Fundamentals

• Runtime GC Config Options

• .NET Core Performance Improvements

🧠 Pro Tip: In Kubernetes, consider tuning CPU requests and limits in your pod manifests accordingly. Server GC benefits from having dedicated cores and consistent CPU quotas.