admir-live / object-creation-benchmark

Comprehensive benchmarking suite for evaluating various object creation methods in .NET, utilizing BenchmarkDotNet.

.NET Object Creation Performance Analysis

In this analysis, we delve into the performance of different methods for creating objects in .NET, utilizing the benchmarking tool BenchmarkDotNet. Our goal is to understand how each method impacts performance and when to use each technique.

Environment Setup

• Runtime: .NET 8.0.3 (8.0.324.11423), X64 RyuJIT AVX2
• Garbage Collector: Concurrent Workstation
• System: Windows 11, AMD Ryzen 9 5900X, 1 CPU, 24 logical and 12 physical cores
• .NET SDK: 8.0.202

Benchmark Methods

We compared the following object creation methods:

1. Using the new Keyword
2. Activator.CreateInstance with TypeOf
3. Activator.CreateInstance Generic
4. RuntimeHelpers.GetUninitializedObject

Results Summary

Here's a brief overview of the benchmark results for each method:

1. Using the new Keyword

• Mean: 2.754 ns
• StdDev: 0.0777 ns
• Memory Allocated: 24 B

This method is the fastest and most straightforward for object instantiation.

2. Activator.CreateInstance with TypeOf

• Mean: 7.935 ns
• StdDev: 1.4022 ns
• Memory Allocated: 24 B

Using Activator.CreateInstance with the type of the object is significantly slower than the new keyword due to reflection overhead.

3. Activator.CreateInstance Generic

• Mean: 7.935 ns
• StdDev: 0.2119 ns
• Memory Allocated: 24 B

Similar to its non-generic counterpart, this method also suffers from the overhead associated with reflection.

4. RuntimeHelpers.GetUninitializedObject

• Mean: 24.874 ns
• StdDev: 0.3682 ns
• Memory Allocated: 24 B

Creating an uninitialized object is the slowest method, primarily used in special cases like serialization/deserialization.

Analysis and Recommendations

• The new Keyword: Best for general use due to its speed and simplicity.
• Activator.CreateInstance: Useful for scenarios where the type isn't known until runtime but comes with a performance cost.
• RuntimeHelpers.GetUninitializedObject: Recommended only for advanced scenarios requiring uninitialized object creation, such as custom serialization mechanisms.

Conclusion

Choosing the right object creation method depends on your specific needs and performance requirements. While the new keyword is suitable for most scenarios, other methods have their place in more dynamic or specialized contexts.

Detailed Benchmark Results

Method	Mean	Error	StdDev	Median	Ratio	RatioSD	Gen0	Allocated	Alloc Ratio
NewKeyword	2.754 ns	0.0831 ns	0.0777 ns	2.773 ns	1.00	0.00	0.0014	24 B	1.00
ActivatorCreateInstanceWithTypeOf	7.935 ns	0.4756 ns	1.4022 ns	8.471 ns	3.02	0.53	0.0014	24 B	1.00
ActivatorCreateInstanceGeneric	7.935 ns	0.1980 ns	0.2119 ns	7.901 ns	2.88	0.12	0.0014	24 B	1.00
GetUninitializedObject	24.874 ns	0.4153 ns	0.3682 ns	24.842 ns	9.02	0.33	0.0014	24 B	1.00