Time cost for creating a HashSet from an ArrayList

I ran this simple test to get a "feel":

import java.util.ArrayList;
import java.util.HashSet;
import java.util.List;
import java.util.Random;

public class Test {
	public static void main(String... args) {
		List<String> bigList = new ArrayList<String>();
		List<String> smallList = new ArrayList<String>();

		Random random = new Random();

		// builds a 10000 items list made of items
		// with string values generated from random
		// numbers between 1000000 and 1999999
		// this list has a higher chance to have duplicates
		for (int i = 0; i < 10000; i++)
			smallList.add(String.valueOf(random.nextInt(1000000) + 1000000));

		// builds a 1000000 items list made of items
		// with string values generated from random
		// numbers between 1000000 and 1999999
		for (int i = 0; i < 1000000; i++)
			bigList.add(String.valueOf(random.nextInt(1000000) + 1000000));

		int tests = 100;
		
		double smallListTransformationsTotalTime = 0;
		
		for (int i = 0; i < tests; i++) {
			long start = System.currentTimeMillis();
			new HashSet<String>(smallList);
			long end = System.currentTimeMillis() - start;
			smallListTransformationsTotalTime += end;
		}		
		System.out.println("Small list transformation average: " + (smallListTransformationsTotalTime / tests));
		
		double bigListTransformationsTotalTime = 0;
		
		for (int i = 0; i < tests; i++) {
			long start = System.currentTimeMillis();
			new HashSet<String>(bigList);
			long end = System.currentTimeMillis() - start;			
			bigListTransformationsTotalTime += end;
		}
		System.out.println("Big list transformation average: " + (bigListTransformationsTotalTime / tests));		
	}
}

Running this (100 tests) on my computer (i7 quad core using eclipse) yielded the following:

• Small list transformation averaged 0.81ms 
• Big list transformation averaged 196.31ms