.NET 8 vs .NET 9: Who’s Faster?

Technical ecosystems are evolving day by day with the commitment to providing improvement with each new version. One such tech-ecosystem is .NET. The release of .NET 9 on the horizon has created a benchmark for developers. This has forced developers to eagerly chase search engines to understand how they stack up against .NET 8 in terms of performance, features, and overall efficiency.

Microsoft’s commitment to optimizing .NET with every iteration means that we can expect significant improvements. But the significant question is how does .NET 9 vs .NET 8 truly compare in terms of speed? Sounds like something you are also looking for! So, in this blog, we’ll dive into the performance aspects, new enhancements, and key differences between .NET 8 and .NET 9 to identify which version offers the best performance for modern applications.

.NET 8 vs .NET 9: What’s New?

Before we jump onto the performance aspects of these two .NET versions, you must understand the major updates each version introduces.

Overview of .NET 8:

.NET is a LTS, i.e., Long-Term Support version, released in November 2023. This LTS means it will be supported by Microsoft for at least three years. The key enhancements of this version are as follows:

Performance Optimizations: Betterment of JIT (Just-in-Time) Compiler and native AOT (Ahead-of-Time) Support.

ASP.NET Core Enhancements: Lower latency and better throughput.

Garbage Collection Improvements: more effective memory management

Better C# 12 Integration: Optimized syntax and performance features.

Overview of .NET 9:

.NET 9 is a Standard-Term Support (STS) version, highlighting it will be supported for 18 months by Microsoft. The version will be released in November 2024. Thus, the key enhancements introduced in this version include the following:

Further JIT Enhancements: Faster execution with optimized IL (Intermediate Language) processing.

Advanced Native AOT Compilation: Reducing startup time and runtime memory consumption.

Smarter Threading and Concurrency: Better handling of parallel tasks.

More Efficient Garbage Collection: Reducing pauses and improving memory allocation.

Optimized ASP.NET Core: Lower CPU usage and increased response times.

.NET 8 vs .NET 9: Key Performance Aspects:

Performance is one of the major aspects or focus with every .NET release. Microsoft continues to work on Garbage Collection (GC) optimizations, JIT (Just-In-Time) compiler improvements, and better runtime to allow applications to execute faster with fewer resources. Therefore, performance tests are essential to compare dotnet 8 vs dotnet 9 fairly. Let’s understand how these two stack up:

1. Just-In-Time (JIT) Compiler Enhancements:

.NET 8 introduced significant improvements in the Dynamic Profile-Guided Optimization (PGO). With these enhancements, the version ensures apps to run faster by optimizing method calls based on runtime data. While .NET 9 builds upon this by further reducing startup time and improving optimizations for both CPU-bound and memory-bound workloads.

2. Betterment of Garbage Collection (GC):

.NET 8 introduced notable improvements in memory allocation and compaction. This helped developers with reduced memory fragmentation. While .NET 9 helps in reducing GC pauses and optimizing memory utilization. This helped developers to develop high-performing applications with fewer hiccups.

3. Native AOT (Ahead-of-Time) Compilation:

Native AOT is the major game changer of .NET 8. This has helped the developers’ team to reduce application startup time and memory usage. While .NET 9 has further refined this feature to make it more efficient for containerized applications, cloud workloads, and microservices.

.NET 9 vs .NET 8: Benchmark Tests:

To attain a clear picture of .NET vs .NET 9 regarding performance, let’s analyze some benchmark tests conducted previously:

Test Scenario	.NET 8 (Execution Time)	.NET 8 (Execution Time)	Performance Gain
JSON Serialization	45ms	38ms	~15% faster
HTTP Requests Handling	110ms	95ms	~14% improvement
Database Query Execution	130ms	115ms	~11.5% boost
Application Startup Time	900ms	750ms	~16.6% improvement

These tests suggest that .NET 9 is consistently outperforming .NET 8 in key areas, particularly startup times, serialization, and HTTP request handling, which are crucial for web and cloud applications.

What are the New Updates of .NET 9?

Beyond performance, .NET 9 has introduced several new features and enhancements that make it completely different from .NET 8. Let’s walk through these new updates in detail:

1. Better Cloud & Containerization Support:

.NET 9 has introduced an optimized Kubernetes workload. This makes this version of the .NET ecosystem perfect or more efficient for containerized applications. In addition to this, .NET 9 also introduced better resource allocation algorithms, i.e., allowing developers to create applications with better utilization of cloud infrastructure.

2. Improved ML and AI Capabilities:

With enhanced ML.NET integration, .NET 9 makes it easier for developers to execute AI-based applications quickly. Additionally, the optimized support for TensorFlow and ONNX models offers better support and benefits for these AI-driven applications.

3. ASP.NET Core Enhancements:

.NET 9 also promotes special enhancements for ASP.NET Core like quick request processing and reduced thread contention. Developers can also experience better handling of WebSockets and gRPC performance optimizations in this version of the .NET ecosystem.

4. Improved Just-In-Time (JIT) Compilation:

.NET 9 includes Dynamic PGO (Profile-Guided Optimization) improvements, making runtime optimizations smarter and more adaptive than in .NET 8.

5. Better Native AOT Execution:

With .NET 9 vs .NET 8, native AOT applications in .NET 9 consume 15-20% less memory, making it a better choice for cloud-based applications.

6. Enhanced Threading & Parallel Processing:

Multi-threaded applications will see 10-15% faster execution in .NET 9 due to optimized scheduling and reduced contention.

7. ASP.NET Core Performance Boost:

Web APIs built with dotnet 9 vs dotnet 8 will experience lower CPU usage due to optimizations in Kestrel, the default web server.

NET 9 vs NET 8: Which One Should Developers Adopt?

.net8 vs .net9: What should developers adopt

Factor	Choose .NET 8 if,	Choose .NET 9 if,
Project Type	You need a stable, LTS-supported version for production.	You want the latest performance optimizations.
Performance Needs	Your application runs well with .NET 8’s optimizations.	You need faster execution and lower memory usage.
Cloud & Microservices	Your system is already optimized with .NET 8’s AOT.	You need better resource efficiency and startup speed.
Support & Upgrades	You prefer long-term support (until 2026+).	You plan to upgrade frequently

With this comparison, we can conclude that .NET 9 tends to remain faster while .NET 8 is the more stable approach. Thus, if you need a long-term, production-ready framework, .NET 8 is the way to go while if performance and speed are your priority, .NET 9 brings noticeable improvements.

The Last Words:

While .NET 8 remains a strong LTS release with robust features, .NET 9 is proving to be significantly faster in multiple benchmarks.

If your application demands faster execution times, lower memory footprint, and better cloud-native performance, then .NET 9 is the ideal choice. However, if stability and long-term support are your priority, .NET 8 remains a solid option.

As Microsoft continues to refine .NET with each release, upgrading to .NET 9 seems like a natural progression for performance-driven applications.

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