Rotating-Cube Applet Performance Test

The following Java™ applet animates the three-dimensional rotation of a cube. While doing so, it rates your computer system's performance: the lower-right corner displays the percentage of the programmed cube-redraw rate that your system actually supports.

You can use the applet to quantitatively compare the applet-animation performance of several hardware/software configurations. If you have only one computer, for example, you might try comparing its performance using different Web browsers.

If the applet does not appear after several seconds, or if it continues to appear all gray, you may need to install Java on your computer, or you may be behind a corporate firewall that blocks incoming Java applets.

You can adjust the rate of rotation about the phi and theta axes (the angles of spherical coordinates) with two scrollbars below the cube. Scrolling right = faster, scrolling left = slower. The current settings for the rotation rate about each axis are displayed to the right of the scrollbars.

You can control the rate at which the applet attempts to redraw the cube by adjusting the scrollbar labeled Desired redraw rate. The desired redraw rate you specify with this scrollbar is shown in the Desired redraws/sec box to the right of the scrollbar. You can also toggle the Paint faces and Buffer images buttons to alter the way in which the image is displayed. Painting the faces causes only the front-most faces to be displayed, obscuring the hidden faces of the cube. Buffering the images causes an entire cube-redraw image to be constructed in memory before sending the image to your display subsystem.

The rate at which the cube is actually redrawn on your computer may be less (and for many computers, substantially less) than the rate you specify with the Desired redraw rate scrollbar. The box in the lower-right corner labeled Your computer's performance indicates the actual rate at which your computer is redrawing the cube, expressed as a percentage of your desired redraw rate. For example, if the Cube redraw rate scrollbar is set to redraw the cube 22.2 times per second (the default setting), but your computer can redraw it only 15 times per second, the box labeled Your computer's performance shows 68% of the desired redraw rate.

You should be able to see your computer's performance get better or worse by adjusting the Cube redraw rate. To give your computer a thorough workout, this applet allows you to set the Cube redraw rate as high as 500 times per second, a rate well beyond the performance capability of many personal computers. You may also notice a decrease in performance if you move the mouse rapidly during the animation, or if your computer system is doing some work other than supporting the applet.

Your computer's performance with this applet depends on the combined abilities of your hardware (microprocessor, cache, memory subsystem, video subsystem, etc.), operating system, and Web browser. The performance does not depend on the speed of your communication line since, after downloading, the applet runs entirely in your computer's memory or cache. Bear in mind, however, that the test measures only the performance of this Java applet. The test does not necessarily measure other types of computation or display performance.

We have noticed one interesting anomaly of the redraw rate: within certain narrow ranges of the rate, it is sometimes possible to increase the redraw rate and experience an increase (rather than decrease) in performance.

For more detail about the applet, see the technical implementation.