有没有更快的方法写入stdout？

I am implementing Unix commands in Go as a way to learn more about Go. I have read some articles where people have implemented yes in various and gotten up to 3 gig per second transfer rates. Through trial an error I have gotten my Go implementation to around 1.5 gig per second:

package main

import (
        f "fmt"
        "os"
        s "strings"
)

const bufsize = 1024 * 64

func main() {
        atom := "y
"

        if len(os.Args) > 1 {
                atom = s.Join(os.Args[1:], " ") + "
"
        }

        buf := s.Repeat(atom, bufsize / len(atom))

        for {
                f.Print(buf)
        }
}

Is there a lower level/faster function to print to stdout?