StringBuilder

• https://github.com/rianjs/DotNetPerfTesting/blob/master/PerfTesting/PerfTesting/Strings/StringBuilderTests.cs

.NET Core 2.2 on Intel 64

BenchmarkDotNet=v0.10.14, OS=macOS 10.15.3 (19D76) [Darwin 19.3.0]
Intel Core i7-8850H CPU 2.60GHz (Coffee Lake), 1 CPU, 12 logical and 6 physical cores
.NET Core SDK=2.2.100
  [Host] : .NET Core 2.2.0 (CoreCLR 4.6.27110.04, CoreFX 4.6.27110.04), 64bit RyuJIT

Method	Mean	Error	StdDev	Median
StringConstructor	117.12 ns	2.284 ns	2.889 ns	118.00 ns
BuilderWithAppend	142.65 ns	3.012 ns	5.658 ns	141.37 ns
PerfectBuffer	53.28 ns	1.762 ns	5.083 ns	52.49 ns
NaiveBuffer	63.91 ns	1.974 ns	5.757 ns	61.87 ns
BigChunkWithTruncation	1,426.63 ns	30.852 ns	54.034 ns	1,412.05 ns
SmallChunkWithTruncation	180.55 ns	3.777 ns	3.709 ns	180.68 ns
BigChunkWithConditionalAppend	1,422.85 ns	18.616 ns	16.502 ns	1,417.22 ns
SmallChunkWithConditionalAppend	179.62 ns	4.050 ns	11.554 ns	174.70 ns

.NET 8 on M3 Mac

BenchmarkDotNet v0.13.12, macOS Sonoma 14.4 (23E214) [Darwin 23.4.0]
Apple M3, 1 CPU, 8 logical and 8 physical cores
.NET SDK 8.0.100
  [Host]   : .NET 8.0.0 (8.0.23.53103), Arm64 RyuJIT AdvSIMD
  ShortRun : .NET 8.0.0 (8.0.23.53103), Arm64 RyuJIT AdvSIMD

Job=ShortRun  IterationCount=3  LaunchCount=1  
WarmupCount=3  

Method	Mean	Error	StdDev	Gen0	Gen1	Allocated
StringConstructor	51.81 ns	1.355 ns	0.074 ns	0.1042	0.0001	872 B
BuilderWithAppend	60.67 ns	1.051 ns	0.058 ns	0.0802	-	672 B
PerfectBuffer	19.25 ns	0.187 ns	0.010 ns	0.0478	-	400 B
NaiveBuffer	24.85 ns	0.512 ns	0.028 ns	0.0813	-	680 B
BigChunkWithTruncation	226.90 ns	4.674 ns	0.256 ns	0.1566	0.0002	1312 B
SmallChunkWithTruncation	34.06 ns	1.543 ns	0.085 ns	0.0258	-	216 B
BigChunkWithConditionalAppend	242.51 ns	7.410 ns	0.406 ns	0.1564	-	1312 B
SmallChunkWithConditionalAppend	39.38 ns	49.968 ns	2.739 ns	0.0258	-	216 B
InterpolateAppend	998.99 ns	11,113.002 ns	609.141 ns	0.0935	-	792 B
NaiveAppend	465.65 ns	135.848 ns	7.446 ns	0.1326	-	1112 B
GuidInterpolation	25.12 ns	3.886 ns	0.213 ns	0.0210	-	176 B
GuidStringBuilder	91.86 ns	21.954 ns	1.203 ns	0.1204	-	1008 B