using BenchmarkDotNet.Attributes;
using BenchmarkDotNet.Running;
using System;
[MemoryDiagnoser(false)]
public class RandomBenchmark
{
[Params(10000)] public int A;
private readonly Random _random = new Random();
public int MethodA() => _random.Next(1, 100);
public int MethodB() => new Random().Next(1, 100);
[Benchmark]
public int BenchA()
{
int result = 0;
for (int i = 0; i < A; i++) result += MethodA();
return result;
}
[Benchmark]
public int BenchB()
{
int result = 0;
for (int i = 0; i < A; i++) result += MethodB();
return result;
}
public static void Main() => BenchmarkRunner.Run<RandomBenchmark>();
}

| Method | A | Mean | Error | StdDev | Allocated |
|------- |------ |------------:|---------:|---------:|----------:|
| BenchA | 10000 | 80.88 us | 0.489 us | 0.434 us | - |
| BenchB | 10000 | 1,490.26 us | 9.404 us | 8.797 us | 720,001 B |