Java SE (Java Platform, Standard Edition)

I've made some calculations to measure speed of PixelWriter, and results are not good, as I can see.

Shortly: it takes 5-10 milliseconds to renew 2 megapixel WritableImage ( with Sandy Bridge 2500 and Radeon 6850 ), and I think it is a quite slow. But maybe I've made wrong test. Please, can anybody take a look and relaunch the code?

Other examples would be cool to see!

import java.nio.IntBuffer;
import java.util.Random;
import java.util.logging.Level;
import java.util.logging.Logger;
import javafx.animation.KeyFrame;
import javafx.animation.Timeline;
import javafx.application.Application;
import javafx.beans.InvalidationListener;
import javafx.beans.Observable;
import javafx.event.EventHandler;
import javafx.scene.Scene;
import javafx.scene.image.ImageView;
import javafx.scene.image.PixelWriter;
import javafx.scene.image.WritableImage;
import javafx.scene.image.WritablePixelFormat;
import javafx.scene.layout.StackPane;
import javafx.stage.Stage;
import javafx.stage.WindowEvent;
import javafx.util.Duration;

class BackWorker implements Runnable {

    int width;
    int height;
    int[] data;
    boolean runOk = true;

    public BackWorker(int w, int h) {

        width = w;
        height = h;

        data = new int[w * h];

        (new Thread(this)).start();
    }

    @Override
    public void run() {

        Random rand = new Random();

        while (runOk) {
            try {
                Thread.sleep(10000);
            } catch (InterruptedException ex) {
                Logger.getLogger(BackWorker.class.getName()).log(Level.SEVERE, null, ex);
            }

            for (int i = 0; i < 100000; i++) {

                int a = rand.nextInt(width);
                int b = rand.nextInt(height);

                int randomColor = rand.nextInt();

                data[b * width + a] = randomColor;
            }
        }
    }
}

public class JavaFXApplication12 extends Application {

    static final int W = 1600;
    static final int H = 1000;
    Timeline t;
    BackWorker backWorker;
    int iterationNumber = 0;

    @Override
    public void start(Stage primaryStage) {


        final WritableImage wim = new WritableImage(W, H);

        backWorker = new BackWorker(W, H);

        final PixelWriter pw = wim.getPixelWriter();

        final WritablePixelFormat<IntBuffer> format = WritablePixelFormat.getIntArgbInstance();


        t = new Timeline();

        t.getKeyFrames().addAll(
                new KeyFrame(Duration.ZERO),
                new KeyFrame(Duration.INDEFINITE));

        t.currentTimeProperty().addListener(new InvalidationListener() {
            @Override
            public void invalidated(Observable o) {

                long timeStart = System.nanoTime();

                pw.setPixels(0, 0, W, H, format, backWorker.data, 0, W);

                System.out.println(System.nanoTime() - timeStart);

            }
        });

        t.playFromStart();

        ImageView iview = new ImageView(wim);

        StackPane root = new StackPane();

        root.getChildren().add(iview);

        Scene scene = new Scene(root, W, H);

        primaryStage.setOnCloseRequest(new EventHandler<WindowEvent>() {
            @Override
            public void handle(WindowEvent t) {

                backWorker.runOk = false;
            }
        });

        primaryStage.setTitle("Hello World!");
        primaryStage.setScene(scene);
        primaryStage.setResizable(false);
        primaryStage.show();

    }

    public static void main(String[] args) {
        launch(args);
    }
}