FULL PRODUCT VERSION :
java version "1.8.0_121"
Java(TM) SE Runtime Environment (build 1.8.0_121-b13)
Java HotSpot(TM) 64-Bit Server VM (build 25.121-b13, mixed mode)

ADDITIONAL OS VERSION INFORMATION :
Microsoft Windows [Version 6.1.7601]

EXTRA RELEVANT SYSTEM CONFIGURATION :
AMD Radeon HD 6700

A DESCRIPTION OF THE PROBLEM :
The rendering performance is visibly worse when you draw shapes with non-solid strokes instead of solid. In the attached sample code you can drag JavaFX Line with the mouse. If the Lines are drawn with a dashed stroke the movement jerks.

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
- Start the attached sample.
- Drag the mouse.
- Observe the problem.

- Set the instance variable "dashed" to false.
- Restart the sample.
- Drag the mouse.
- The performance is now much better.

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
The rendering performance should be independent of the stroke dash.
ACTUAL -
The rendering performance of non-solid lines are much worse.

REPRODUCIBILITY :
This bug can be reproduced always.

---------- BEGIN SOURCE ----------
import javafx.application.Application;
import javafx.scene.Group;
import javafx.scene.Scene;
import javafx.scene.paint.Color;
import javafx.scene.shape.Line;
import javafx.scene.shape.StrokeLineCap;
import javafx.stage.Stage;

/**
 * Sample to reproduce the poor rendering performance of dashed strokes.
 * Change the value of the variable dashed to switch between solid and non-solid strokes.
 * Drag the mouse to watch the rendering performance.
 */
public class TestDashStyle extends Application {
  private boolean dashed = true;

  @Override
  public void start(Stage primaryStage) throws Exception {
    primaryStage.setTitle("Performance of Non-Solid Lines");

    Group root = new Group();

    for (int i = 0; i < 1000; i += 10) {
      Line line1 = createLine(i, 0, i, 1000);
      Line line2 = createLine(0, i, 1000, i);
      root.getChildren().addAll(line1, line2);
    }

    Scene scene = new Scene(root, 1200, 800);
    scene.setOnMouseDragged(event -> {
      root.setTranslateX(event.getX());
      root.setTranslateY(event.getY());
    });

    primaryStage.setScene(scene);
    primaryStage.show();
  }

  private Line createLine(double startX, double startY, double endX, double endY) {
    double thickness = 1;
    Line line = new Line(startX, startY, endX, endY);
    line.setStroke(Color.RED);
    line.setStrokeWidth(thickness);
    if (dashed) {
      line.setStrokeLineCap(StrokeLineCap.SQUARE);
      line.getStrokeDashArray().addAll(0.0, 3.0 * thickness);
    }
    return line;
  }
}

---------- END SOURCE ----------