String concatenation peformance in Go

/*

Cloned from: https://pastebin.com/ukxUmAwa

AMD Athlon64 X2
2GB DDR2

Go 1.5.1 linux/amd64

Ubuntu 15.10
Linux asus 4.2.0-19-generic #23-Ubuntu SMP Wed Nov 11 11:39:30 UTC 2015 x86_64 x86_64 x86_64 GNU/Linux

BenchmarkStringSprintf-2         100      10140559 ns/op     5518024 B/op       4616 allocs/op
BenchmarkStringJoin-2            200       6962496 ns/op     5388737 B/op       2000 allocs/op
BenchmarkStringAdd-2             500       3440360 ns/op     2694352 B/op        999 allocs/op
BenchmarkStringWrite-2         30000         54597 ns/op       18656 B/op          8 allocs/op
BenchmarkStringAppend-2        30000         41325 ns/op       20736 B/op         13 allocs/op
BenchmarkBytesJoin-2             300       4883126 ns/op     2694449 B/op       1001 allocs/op
BenchmarkBytesAppend-2         30000         53491 ns/op       20736 B/op         13 allocs/op
BenchmarkBytesWrite-2          20000         64233 ns/op       18656 B/op          8 allocs/op

Feel free to change the LIMIT.

*/
package test

import (
    "bytes"
    "fmt"
    "strings"
    "testing"
)

var (
    s1 = "local"
    b1 = []byte("local")
)

const LIMIT = 1000

func BenchmarkStringSprintf(b *testing.B) {
    var q string
    for i := 0; i < b.N; i++ {
        for j := 0; j < LIMIT; j++ {
            q = fmt.Sprintf("%s%s", q, s1)
        }
        q = ""
    }
    b.ReportAllocs()
}

func BenchmarkStringJoin(b *testing.B) {
    var q string
    for i := 0; i < b.N; i++ {
        for j := 0; j < LIMIT; j++ {
            q = strings.Join([]string{q, s1}, "")
        }
        q = ""
    }
    b.ReportAllocs()
}

func BenchmarkStringAdd(b *testing.B) {
    var q string
    for i := 0; i < b.N; i++ {
        for j := 0; j < LIMIT; j++ {
            q = q + s1
        }
        q = ""
    }
    b.ReportAllocs()
}

func BenchmarkStringWrite(b *testing.B) {
    q := new(bytes.Buffer)
    for i := 0; i < b.N; i++ {
        for j := 0; j < LIMIT; j++ {
            q.WriteString(s1)
        }
        q = new(bytes.Buffer)
    }
}

func BenchmarkStringAppend(b *testing.B) {
    var q []byte
    for i := 0; i < b.N; i++ {
        for j := 0; j < LIMIT; j++ {
            q = append(q, s1...)
        }
        q = nil
    }
    b.ReportAllocs()
}

func BenchmarkBytesJoin(b *testing.B) {
    var q []byte
    for i := 0; i < b.N; i++ {
        for j := 0; j < LIMIT; j++ {
            q = bytes.Join([][]byte{q, b1}, nil)
        }
        q = nil
    }
    b.ReportAllocs()
}

func BenchmarkBytesAppend(b *testing.B) {
    var q []byte
    for i := 0; i < b.N; i++ {
        for j := 0; j < LIMIT; j++ {
            q = append(q, b1...)
        }
        q = nil
    }
    b.ReportAllocs()
}

func BenchmarkBytesWrite(b *testing.B) {
    q := new(bytes.Buffer)
    for i := 0; i < b.N; i++ {
        for j := 0; j < LIMIT; j++ {
            q.Write(b1)
        }
        q = new(bytes.Buffer)
    }
}