jdk 1.4.2_04 performance on Solaris x86 is double the performance on Sparc
Time on Toshiba laptop Tecra 8100 600 MHz Solaris x86 9 :
5684
Time on 280R 750 MHz Solaris 9:
10310


Example used:

import java.io.*;


class Test {

public static void main (String args[]) {

Test t = new Test(args);
}


Test(String [] args) {
                long millis;
                StringBuffer buffer = null;

if (args.length==1) {
System.out.println("Priming...");
for (int i=0; i<15000; i++) {
buffer = test(1);
}
}


System.out.println("Press return to continue.\n");
try {
int i = System.in.read();
} catch (IOException e) {
System.out.println(e);
}

System.out.println("Testing...\n\n");
                millis = System.currentTimeMillis();
buffer = test(1000000);
                System.out.print("Durata: ");
                System.out.println((System.currentTimeMillis()-millis));

}





private StringBuffer test(int iterations) {
StringBuffer buffer = null;

for(int k = 0 ; k < iterations; k++)
{
buffer = new StringBuffer(" ");
String a1 = "cgghghghghghhhhhgd";
String a2 = "12";
String a3 = "XXXXXXX";
String a4 = "";
String a5 = "";
String a6 = "-ggggggggggggg";
String a7 = "-";
String a8 = "ggggg-";
char c;
int i;
int j = 0;


String str = a1;
for(i=0; i<str.length(); ++i) buffer.setCharAt(j+i, str.charAt(i));
j += 20;
str = a2;
for(i=0; i<str.length(); ++i) buffer.setCharAt(j+i, str.charAt(i));
j += 20;
str = a3;
for(i=0; i<str.length(); ++i) buffer.setCharAt(j+i, str.charAt(i));
j += 20;
str = a4;
for(i=0; i<str.length(); ++i) buffer.setCharAt(j+i, str.charAt(i));
j += 20;
str = a5;
for(i=0; i<str.length(); ++i) buffer.setCharAt(j+i, str.charAt(i));
j += 20;
str = a6;
for(i=0; i<str.length(); ++i) buffer.setCharAt(j+i, str.charAt(i));
j += 20;
str = a7;
for(i=0; i<str.length(); ++i) buffer.setCharAt(j+i, str.charAt(i));
j += 20;
str = a8;
for(i=0; i<str.length(); ++i) buffer.setCharAt(j+i, str.charAt(i));


}
return buffer;

} // end method test

  private static void delay(int time) {
    try { Thread.sleep(time);
                } catch (InterruptedException e) {
                  System.out.println("Interrupted!");
                        e.printStackTrace();
                }
  }


}